I would really recommend 6gb or more ram, if you are planning on 5-boxing. A decent rule of thumb is 1gb for the operating system, and 1gb extra per toon you which will be run at one time.



With one existing account, I would daisy chain the RAF.
That will let you make the most out of granted levels across the team.
For every link in the chain (A to B, B to C etc) you need to boost 2 toons for full effect of cascading levels.

If you want the cascading levels to all add up to full toons, go something like:
A -- B -- C
A -- D -- E
And then boost 4 on BCDE with A.
Resulting in 2 extra toons on B/D from CE, plus 2 extra toons on A from B/D.
And then 2 additional toons on A, 1 each from B/D based on levels granted from C/E.

It is probably easier/better...
To just link:
A -- B -- C -- D -- E
Let's say you boost the same four toons, on BCDE.
A-D each get 2 toons from the account linked after it (4 x 60 levels gained = 240 / 2 = 120 levels to grant = 2 toons).
In this situation, the ideal option would be to boost an even number of toons, get one extra toon per account (except the last one in the chain) for each pair that is boosted. And to then possibly transfer a toon or a few toons to E. Even without the transfer, E will have several toons from the boosting.



A semi-geared tank will be faster boosting then an AoE caster.
But I've done boosting both with a tank and with a DPS.
A 70 hunter in Kara level gear (T4) was more the adequate for DM/Stockades/SM/ZF boosting, and while not strong enough for Strat/Scholo, easily boosted through quests in Searing Gorge, Tanaris, Un'Goro, Sithilus, W/E Plaguelands etc, for the last 15 levels or so.