I would recommend queen-sized beds. I'm assuming you have room for them, since you listed them as an option. Here's what I'm thinking:
- You expect your girls to be tall. I am 5'10" and was already 5'7" by the time I was 11 years old. I found twin/double beds short.
- A queen-sized bed makes a much nicer guest bed than a double if you are ever using the room for other people.
- If you reduce the variety of bed sizes in your home, you reduce the amount of bedding you need and have greater flexibility. You need one set for each bed, and one or two spares.
- Since queen is such a popular bed size, you can get some really good deals on good quality mattress sets, bedframes, bedding.
Another thought (which worked very well for us):
If you buy two twin extra-long mattress sets, they can be used individually. They can also be set up together to make a king-sized bed. (One small consideration is bed frames: Frames on castors with bolt on headboards/footboards is no problem. But if you are set on a bedframe with wooden side rails, you will have limited options or need to get special longer side rails).
I think in-room desks are a big waste for a lot of kids. There were four kids in my family growing up. No one used desks in bedrooms. They were just a junky mess. We always preferred doing homework while sprawled on our beds, or at the kitchen table. It will probably be the same as my own children get older.
We have two matching chests of drawers (three drawers each) in the room our girls share. This is more flexible than a classic double-wide dresser that comes in a lot of bedroom sets.
I never bought a baby change table but we did buy a buffet (bottom only) from IKEA. It has three cupboard doors on it. Has been awesome for kid clothing and diaper storage and some day I will move it out of the kiddie room.
A medium colored wood will hide dirt/dust a lot better than white painted wood will. It will also be more forgiving of nicks and scratches.