Here's a different consideration. Your 600 and 1200 are both of more recent surface mount construction. So are the 4000 and CD32. They are working now, but, if a chip goes bad, most likely you will have to find someone to repair the motherboard, if you can....
I have refurbished a number of Amiga models and use routinely an A4000T and X1000. The A500 & A600 are very limited in their capabilities and expandability; the A1200 can be expanded and even towerized but it is a real pain keeping it all connected and working. The A3000 is beautiful but poorly designed, cramped inside and full of sharp edges that make in a "bloody" pain. The A4000T is roomy easy to work on (except for the drive cage), has IDE and good SCSI, allows all sorts of expansion, but are hard to find for sale. The A4000D has less room and expandability than the T, but is still an easy beast to "live" with.
Repairs used to be a problem until a month ago when I sent 4 A4000D and 1 A4000T motherboards to Anthony Hoffman for repair. I had the four A4000Ds repaired and returned in under a fortnight. The T needed an SCSI 53C710 smd chip replaced that he had to order and it took another week. Phase5 products can be repaired by Stan Sędłak (3 CSPPCs took about 2+ weeks from out my door to back in my hands).
