Tyler,
The best advice that I can give you is to purchase the best that you can afford. Look at the details such as instrumentation. On the list of four cars at least one has the wrong instruments. One looks like it has reproduction instruments. One appears to have a 750 motor, but one other one has either an 850 or 1050 motor, along with it's dual down-draft carburetor. This combination never came on the DB.
Probably the most expensive part is a Mille Miglia crankshaft. The DB was manufactured prior to the introduction of the 600D and should therefore have a 600 block and a 600 gearbox, with the parking brake on the gearbox.
I would be pleased to help you out. I have a DB on my website at the moment, as well as a 1000GT with very good history.
Paul Vanderheijden
www.scuderiatopolino.com