We have banked blood at one birth in our facility, and it was such a pain in the ass, we really don't recommend it. Maybe if you are birthing with someone who has done this alot, it would be alot easier.
We had never done it before, and so while the mom was in labor, the mw and I (I'm the nurse) read and re-read the instructions. Then, although the mom really wanted to labor and push in the tub, we had to make her choose between getting out of the tub to get the cord blood or staying in the tub and not getting the blood. So the collection of the cord blood really dictated where the mom birthed. It was a freakin mess. The collection kit required a heck of alot more than 1 ounce, let me tell you. The collection kit looked like the opposite of a blood tubing, if you know what I mean. It stated that we needed to collect as much as possible, and we collected at least 40ccs, I would guess. Blood I personally think should have been in the baby. Maybe that is something that you should ask about when you explore collection agencies. We had to clamp the cord before it was done pulsating, too, something we never usually do.
I guess you should check with your midwife and see how comfortable she is with the entire event. It would suck to have to decide a caregiver based on their ability to collect cord blood. We try to be as low intervention as possible; as a result, we are not proficient in such a procedure (I know they do this in the hospital more frequently) and it ended up dictating mom's position for birth and early cord clamping. Also, we spent a significant period of time during transition and immediately after birth dinking with the damn collection kit set-up, time we really would have rather spent with the mom and baby!
Lori