Your welcome.
Just for you (and my parents) I went to the local Mycom this afternoon. It turns out their "prefab" systems are indeed prefab. If you want something else, you have to get a custom PC. I expect the price of a custom PC to be pretty much identical to the prefab system, though.
The prefab systems look pretty slick, and are also pretty quiet. My parents bought one, and I got to testdrive it.
- Printers... In general, the higher the price of the printer, the lower the price of ink. I bought a midrange model (deskjet 5150), but because I hardly use it, I think it would have been cheaper to buy a lower-end model. At the moment I'm thinking of buying an all-in-one, so that I can photocopy stuff. I'll be getting the cheap model this time.
- Serial port: the low-end Mycom system my parents bought has a serial port. I wouldn't be surprised if a lot of motherboards still have them, perhaps hidden away somewhere.