You should be able to achieve what you are after in the allotted time.

I'm 2 months into my RAF and have the following

5x Mage 58 - ready to grind winterspring rep
4x Warlock 60
4x hunter 20 - currently running (7 hours played)
1x Rogue 60
1x Priest 60

still left to do:
4x Druid
2x RAF Allotted - not yet decided

I already have:
1x Warlock 70
1x Paladin 70
1x Hunter 60
1x Druid 60
5x Shaman 60

I play for between 1 - 3 hours per day and between 4-16 hours at weekends depending on RL commitments

I would have been further along the completed list, but for a two week outatge on my home ADSL (Pipex suck)