At this moment I have the following collection:
* Amiga 4000/040 with Cybervision 64/3D, Buddha/Catweasel and XSurf network card. I believe it has 8 MB Fast RAM.
* Amiga 2000 with GVP Combo 030 card and a separate GVP SCSI controller. This one has 4 MB Fast RAM.
* Amiga 1200 with Blizzard 1220/4
All have Kickstart 3.1 ROMs. There's a number of peripherals as well.
Furthermore, I have a Pegasos 1 and a Commodore 64.
All those machines still need to be set up since I have only a very small desk in my new house (a bigger desk is still on my shopping list), so for the moment I'm stuck with WinUAE/Amikit. Every now and then I grab one of my miggies to do some tweaking/installing, but then they go back in the closet.
I'm thinking of selling my A1200 and A2000 and finding myself a non-yellowed A500 with ECS chipset. I will use the A500 for games and minor utilities, the A4000 will be for the more heavier work. On the Pegasos I will run MorphOS, just for fun and to get to know it a bit.
Concluding: if you want a not too big Amiga collection, go for the A4000(T) for expandability, and take an old one just for fun. The A4000 can virtually do anything Amiga that you want, more than the A3000. The 3000 is the most beautiful Amiga though (in my opinion)