Re: @ tfewster
I have never had stability issues with desktop PCs and Linux (generally Ubuntu), but have had some buggy wifi with laptops and occasional no-display. But equally some people have stability/BSOD with various Windows machines for never adequately explained reasons.
If you want ones that are good and definitely work then check out Entroware:
Otherwise some folk have decent results from cheap HP laptops, and you can get one *basic* model with only FreeDOS for under £200 with various people saying it worked fine with Linux: