If you read the article I linked it basically says that unless you're going to overclock the AMD and Intel mid-range chips come out about the same.
So, the choice of which chip basically comes down to the question "are you going to overclock?".
I think if you're going to use this for recording then you want it to be fairly quiet? In which case you perhaps want an air cooler with a large slow moving fan. This probably limits the extent to which you can overclock.
I'm not sure what sort of noise watercooling makes, but I suspect it's going to be too expensive in comparison to air cooling.
So, all in all AMD might be a good choice. In which case I would look at socket AM2 hardare (instead of socket 939 .. what do the rest of you think?)
I would use http://computers.pricegrabber.co.uk/
to find something that has the features you need.
The AMD AM2 chips range from £40 upwards.
The AM2 compatible motherboards range from £35 upwards, the cheaper ones are mostly Micro ATX which basically just means they take up less room and generally have less PCI slots, usb and firewire ports. I don't expect you will need a large number of PCI slots perhaps see if you can get:
1x PCI-E 16x (for future graphics upgrades)
3x PCI slots
As for RAM well it depends on what the motherboard supports but I would expect you to need DDR2 800mhz AKA PC-6400, you can get 1gb from as little as £26 but I would look at getting a 2gb dual channel kit for something like £45+
We didn't figure out exactly what component in your current system is causing the blue screens so we're not sure if the motherboard (disk controllers), the ram, or the disk drive itself is at fault, or it could simply be a driver issue.