PS2 is too new and complicated to emulate and we won't be seeing those in quite a while, you will also need a mean PC to run it the way it is supposed to. PSX emulation is quite advanced now. No emulator emulates the machine it is supposed to emulate at a perfect 100% but looks to emulate it as close as possible.
If you have an original machine and compare the original hardware and the emulated hardware side by side you will see the small differences here and there. Just FYI, thx God I have what I call my small console museum and can certify the differences.
(In case you're wondering my museum is currently comprised of: Atari 2600, NES,SNES, N64, GBA, Genesis with CD and 32X, Saturn, Dreamcast, two Playstation ones, Xbox)