I sent this (and another, earlier reply) by email as well but thought I'd follow up here as well.
One last thing to check, we sent an 80 pin IDE cable -did you use it? From the pics it looked like you had but it's hard to tell for sure. Newer HD's often don't play well with the old 40 pin IDE cables which is probably the reason 40 pin cables are no longer used.
The fact that your Motherboard now won't get past POST to let you in the BIOS sounds like there are definitely issues with the MB.
Any current PC components should be fine. I know of nothing current that won't run.
We currently use an AMD 7500 dual core, I have two Intels at home, one a quad and one dual core and I know of nearly a hundred of flavors of CPU's & clock speeds that have come in the last two years and all of them work without a hitch.
Did the IDE port on the board work with the old HD? ie. Was it tested recently?