If I were you. I'd search Craigslist for a somewhat decent bike (the more good parts attached the better) and give it a semi complete overhaul by repacking/replacing all the bearings etc.

That will provide a LOT of relatively inexpensive "education" while you search for your "good" frame.
Sell that bike and recoup your money.
By that time, you'll know much more about all the different "standards" etc.
You might even stumble across a good old double butted CrMo frame in the meantime.