If you like the a500, you should try to max it out. Nowadays it's hard to find powerful expansion boards, but can be possible. Also, if you manage to get a converter for the expansion port to zorro, you could add a graphics card to it, i saw on the net long time ago a guy that had his 500 with rtg. But finding a500 parts nowadays is very hard. It's easier to get parts for a a1200, hence some suggestions made to you by mates on this forum, but if you really like the idea of having the 500 maxed out, go for it.