IMO the perfect Amiga is as follows:
A1200 in original desktop case
030 accelerator (preferably Blizzard) with fast RAM on board
Compact flash to IDE adapter with 4GB card
PCMCIA compact flash adapter like EasyADF
Lots of WHDLoad games 
This is having gone through two basic A1200s upgraded to the max into towers, plus an A4000D similarly upgraded, and all sold and gone back to the setup above
--
moto
I agree, once you go beyond the desktop case (and away from using the classic chipset) it all becomes a bit silly. What's the point in building an 'Amiga' that is only using the MB as a fixing plate to joint the various upgrades together
You did forget to add an IndivsionAGA to that list though!
Just get a 1200 with an IndivisionAGA, a (cheap) 4GB CF and a cheap 4mb memory card (no need for FPU) then install OS 3.1 + WHDLOAD and hook up some big speakers
You'll have an nice retro machine that will run most classic software with the best possible display for not much dollar.
