Romulation is perfectly safe for lots of roms. I use it all the time. I also use Dolphin Emulator (Probally the only Wii/GameCube Emulator out there.)
I had a Intel Core i5 CPU " 2.67 GHz, 4GB Ram. And It was very laggy, so bear that in mind!
Best website for downloading GameCube ROM games that you have used?