Information overload!

But to sum it all up, if I want to RAF while keeping my 5 "main" accounts, the best way for me would be to follow Ualaa's first suggested option. That means buying a total of 4 accounts for RAFing purposes only (2 at a time), and use one of my current accounts as booster. To get the most out of RAF I'll probably need to upgrade the accounts to WotLK.
First thought was "fuck no! too expensive". Then I thought about the time it took me to get the current team to 77 without heirlooms or RAF and it seems like a good deal all of a sudden
Guess I need to sit down with pen and paper and plan accounts/chars. Any tips for that?

Also, a bit off topic, how do you handle DKs? I mean they start at 55 and by the time they leave their zone they are 57-58 iirc. Do you level a healer for them to the same level, or just take a high level healer from the fifth account?