The Ultimate Emulation Machine

New here, never emulated anything but pokemon red but i need a summer project.

my idea was to take my old computer, install linux on it (free, less overhead, more customization) and basically create the ultimate arcade machine with ever game worth emulating. then i thought of all of the problems i might have and came here, so heres my questions.

are linux emulators typically as good as windows emulators?
ive used 2 different gameboy emulators on windows XP and one was total crap

what kind of hardware is required to emulate PS2 and Xbox?
i have a Sempron 2800+ or a Pentium 4 i could use but im not sure they will manage.

it it difficult to configure peripheral controllers?
i would like to get some gamepad working and possibly analog sticks

Your pentium 4 wouldn't be enough to emulate PS2 and Xbox, both require Dual Core at the very least. As far as Linux, many are hit and miss. Mupen64 is the best N64 emulator for Linux, and you can try some of the other Linux emulators to see which ones are good or not, you just got to experiment a little. As far as controllers go, I have no experience in that area, but there is another user that is qualified to answer you, he might answer.