I have used UTSource several times to get parts for my home built Z80 and PDP8 machines. Prices are reasonable and always been very pleased with the parts.
No relationship.... just a satisfied customer.
Wanted: S-100 Bus components - please PM me if you have any. They don't even need to work!
I've got one coming from the UK now. Still wouldn't mind one sooner as this machine is really starting to frustrate me.
So far I've replaced the RAM twice, the SAM, CPU and the LM1889 (the last one was to improve the video output which was really dull). It still leaves the ROM chips but as I can blind type sound commands and get output, plus control the tape motor relay I doubt it is a ROM issue. But you never know.