Like it says in the earlier post it depends what you want to do
I myself LOVE the CD32 and with the SX32 pro addon your gonna have a dream CD32 so to speak.
Fitted with a HD and more ram i don't think there will be much more you want to do.
As for running the powerfull stuff just use your PC with Emu's and stuff like Amithlon, Winuae etc.
It will run nearly everything you want it to anyway all the aga compatable games will run ok and you will be able to run nearly all the demo's.
As for the real serious new stuff well you would need a PPC Amiga which would cost you alot anyway..