I agree with WardL and Bartruff1.. I spent a good year on this site reading up on the threads before buying a cobra. The guys on here really know there stuff..
I decided on a factory built ( 1994 build by LA Exotics ) cobra. I searched for a local cobra, so i could have it inspected by my mechanic. If you purchase one from a factory you can call for part numbers ( make sure they are still in business). I chose a simple cobra with a 351 windsor that can be worked on by a garage or I can replace minor things ( seals, belt,
oil and filters, gaskets, bolts etc.) myself. Borg warner transmission and a ford 9" rear, which are reliable and any garage can worked on. Hydraulic clutch and disk brakes all around. I also looked for a gel coated fiberglass body. I like the older look and didn't want to be nervous about rock chips. The gel coat cleans up nicely when waxed..I was surprised.
After buying it and driving 3000 miles on it I decided to upgrade the fuel pump, converted the suspension to coilovers, and added a manual choke. Other than that, it's been a fun driver with little worries. I don't plan on car shows just want something to tinker with and drive. I drive it on long road trips with my wife..I drive it into work twice a week on good months. As long as you have a good basic setup you can always upgrade along the way. In my opinion, these cars are so light weight a small block V8 will give you plenty HP.
One other thing make sure to get it on a dyno and tuned..Not for horse power but to make sure it's timing and jetting properly. You don't want these engines to run lean... ever....