Recommended Specs for After Effects?

[Dr. Derpface, J.D.]

RAM....all the RAM you can afford. More layers = more RAM needed. Basically, there is no such thing as "too much"

Also, you want decently fast scratch disks. If you can swing it, get a couple inexpensive SSD's and put them in RAID-0. A couple velociraptors would work as well. Either way, be sure you're backing up that volume on a regular basis, since RAID-0 is all about performance, but the 0 also stands for how many bytes you will recover if something goes wrong with either drive.