I like what I'm seeing in reviews:I mean, the i7 4790k (it could be the 4770?) is the most common cpu, period and should run win 7 like a boss (my 4th gen i5 runs win 7) so you sould be able to find that one pretty easy. (i found a few on ebay for around $150)
It looks superior in comparisons to all the other 3rd to 5th gen i7 CPUs I was considering. Looks readily available, so no need for a massive safari through all my legacy parts suppliers. Under my $300 per component limit. Unless someone can come up with a better recommendation (and I much doubt anyone can) I think we got a winner. I'll give it a day or two to see if anyone can prove me wrong, then put the i7-4790k on my procurement list, and start looking for an equally impressive motherboard. Your recommendation looks spot-on, and is much appreciated.