My 13 yr old step son's mom moved him out of state a few years back, and while our situation is quite different than yours (I read the post you linked to), I will share our experience.
In fairness to you, I will start out by being upfront about my bias. I don't generally believe that a parent should move out of state. I believe that whatever issues lie between the adults should not be put upon the children and, in general, chidlren should not be denied regular access to either parent, unelss there is abuse/neglect. You mentioned abuse in your other post, but I'm unclear about if the children were abuse or if that was an issue between the adults. Basically, I'm aware I don't know enough about your situation to stand on my soapbox and tell you what you should do. Like I said, I'll just share my experiences.
When my DSS was about 8 yrs old, my DH's ex petitioned to move out of state. We were (are) in Northern CA and she wanted to move to Northern WA state. My DH was very active and involved in his son's life - consistent visitation (he was with us 35% of the time), consistent payment of CS + health insurance and half of childcare costs + misc items such as clothes, shoes, etc., as needed. His son also has special needs (medical and educational), all of which my DH was consistently involved in facilitating.
She presented a case claiming she could not find work in our area, however in their conversations, she told my DH she wanted a "fresh start" and that she didn't feel she could get that living in the same city as him. My DH showed listing after listing of jobs available in our area, and told the court about her "fresh start" conversations. The judge put the burden of proof on my DH to prove to the court that "the child will be negatively effected by not seeing his fatehr on a regular basis" With all the talk of deadbeat dads and fathter's who are barely involved in their children's lives, I found this appalling. The insinuation was that my DH was unimportant to his son life, except for financailly.
Despite his involvement and positive influence on his son's life, and despite his efforts to show there was work to be had in our area, the court granted her permission to move out of state. The whole court proceeding took about 2 months and included phychological evaluations, as well as conferences with teachers, school adminstrators and DSS's doctors.
Based on this experience, I would have to agree with your attorney. I don't think you will have any problem getting permission to move. The courts tend to lean in favor of the custodial parent, even when the non-cusdotial parents is as involved as my DH was. Sounds like your dc's fathers are not nearly so involved as my DH was, so I don't forsee them being a roadblock to you moving.
So anyway, after my DH's ex moved away, it was very difficult for all of us, including her. The judge ordered monthly visitiation, which included airfare and she had to pay for half of it. She was furious about this, but did it anyway. Becuase of DSS's special needs, he was unable to fly alone, so either my DH would fly up there to visit (incurring hotel and meal costs, as well) or one of them would fly with him, incurring extra airfare costs. It cost both she and my DH a lot of money each month.
She would also sometimes call my DH and complain that their son was too much for her to handle by herself. He took the move VERY hard and was rebelling against his mother A LOT. He was clearly upset with her for moving him away from his dad and he would tell her so, directly and indirectly. He went through a period of months where he would barely speak to her - he would only growl at her. He became increasingly defiant and while he did well academically (better than he was doing in CA, but we chalk that up to WA schools being superior to CA schools), his behavior in school was quite volatile. Lots of acting out, disrupting class, and difficulty making friends.
After two years in WA, she suddenly decided to move back. She claimed it "just didn't work out like she thought it would", but we know better. During her travels for visitation, she would sometimes stay in our area for the weekend while her son visited his dad and during these stays, she met a man and they were dating. Yes, we were thrilled she was returning with my DH's son, and yes, she had a hard time with the move, and I can see how it didn't work out for her in many ways, but it infuriated us that basically it took her getting a boyfriend down here, and all of a sudden, that was what motivated her to move back.
They have been back in the area for the past 2 years and DSS now lives with us (has for almost a year). She agreed to having him live with us because she couldn't handle him and was ready for "her
time to live her
life". Mom sees him 15% visitation (every other weekend, Fri & Sat night, returning Sun afternoon) and that's it. She pays a rediculously low amount of CS (12% of what my DH paid to her) and never buys him anything extra, except for South Park or Beavis & Butthead t-shirts (which he is NOT allowed to wear to school). He comes home from her house on Sun afternoon and his homework folder hasn't even been looked at. (Thanks for the help with making sure he's taken care of!
: ) She has now married the boyfriend and they are pretty much doing their own thing.
The most positive thing that's come out of this situation is that she is SUPER cooperative with us now (used to be very combative about every little thing) because she is scared to death of going back to court. In CA, you see the same judge every time you go to court, so if they end up in court again, she will have to face the same judge and explain why she is not only back in CA, but married and her son lives with us (she painted a nasty picture of my DH in the move away proceedings - lots of lies just so she could get what she wanted). Oh, and she's still working in the same filed that she claimed she couldn't find work for here. The judge will not be pleased with her and she knows it.
Sorry to write such a book, but that's our story. It didn't work out well for her or for us, and it was very, very hard on my DSS.
If you have any questions, I'd be happy to answer and talk with you more about this. Good luck in making your decision. I know it's not easy.