If it were me, I'd go the A4000 route, but there are many pros and cons mentioned in this thread about each computer.
The A1200 is a nice little machine, with various upgrades available. Accelerators are easier to get hold of compared to A4000, but if the goal is to get a 060 accelerator in it, I don't think this conclusion is bullet proof. The downside of the A1200 is that you can not add a graphics card to it, unless you tower and use some sort of busboard.
While towerising, you'll need a keyboard adaptor, and none of them are actually any good. The one I have in my A1200T can not have multiple keypresses, and that is very annoying when playing games. Since games isn't your thing, it's not an issue for you, but might be worth to have into consideration for other planning to do the same.
The A4000 have problems with leaking batteries, that can wreck the board. So can leaking capacitors. Accelerators are more expensive, but on the other hand you can add graphics card, ethernet card, sound card, USB card, etc, straight away and without towerising. Unfortunately, the Zorro cards are a bit pricy. If you'd like to towerise the machine, it's also possible of course, however a new Zorro busboard would be ideal, but not a requirement.
Regarding x56h34s comparison of the BPPC vs CSPPC I would like to add that the BPPC can have 256 MB of fast ram, while the CSPPC can have 128 MB of fast ram. IIRC the ram on the BPPC is 16 bit, while 32 bit on the CSPPC (or am I confused, it's early in the morning)
As others have pointed out; if you aren't going to play games, why go AGA? Demos maybe?
Anyway, most A4000 accelerators can work in the A3000 as well, so if it should be an ongoing projekt, you can get the A3000 upgraded a bit (unless it is already high spec??), buy the A4000 and switch over the accelerators of you want the A4000 to be the main Amiga.
