Knew you'd be pleased :-D
I can't comment on DOOM, as I already had a PPC when I tried the Amiga ports for th first time.
re running old DOS-games:
What about a DOS emulator? Bochs is for free, but for running very old stuff, it should be fast enough if your computer is able to run XP...
And for old Lucasfilm Adventures I'd use ScummVM.