@rhythmsandy you cannot say emiter follower when talking of mosfet power devices, the correct terminology is Source follower. On the other hand MOSFET ( Metal Oxide Field Effect Transistor ) has it's gate electrically isolated from the DS channel, that intails no DC current drawn by the gate no matter the load, but as @Tekko pointed out there is the need for AC current cus of the Ciss of the power mosfet, IRFP has Ciss of 1,2nF, each added pair adds to that capacitance and so the need for some minimum AC current becomes more and more important with each added pair of mosfets, otherwise that large Ciss would have nasty effects on the performance of the output stage. And for an explanatory example let's look at the upper side of the audio spectrum, let say we have 4 pairs of mosfet's and so 4,8nF combined capacity, at 20Khz a 4,8Nf capacitor would have a reactance of about 1,6K ohms, as you can realise that would not be verry good for the signall. How do you circumvent that? you supply enough gate current as so the Ciss is charged fast enough. For 45V per rail 4 pairs of mosfet for 2 Ohms load would be ok indeed.
@rafjr00 using power mosfet;s as the output devices for an power amp is quite different from usoing BJT's, do not forget that MOSFET's are voltage driven devices, but BJT's are current driven devices, so as an output stage with mosfets could do with less than 100mA of gate current, the BJT's for the same load could need more than 1A base drive, that is quite different.
