Well let me tell you this: I still use the old SCSI chip with no problem and my boot drive is an old 500MB SCSI drive. I did put in a Rev 11 buster, but I never needed to do it. I just got the chip fry out of a dead A4000 board. The Ramsey and DMAC are also older and unless you use a board that just wont work witht he older stuff again there is no need to swith them out.
My A3000 is mediator equiped and CSPPC equiped with no problems. I use it for just about everything you can think of. I have a video card, CD burner, sound card, the works. Get the A3000, its the best Amiga ever made without question in my opinion and I am sure several others.