I would wait for something else.
If I read this right it sounds like your looking for something that not only looks good and turns heads but is dependable.
Look at it this way - Do you know if the 50 yr old man was the orig. owner of the Nissan? You never know how it was taken care of from previous owners. And you know he knows people buy cars from older people because they think exactly that! Trust me looks can be deceiving!
I would try to start w/ a good base line, get a body style and make you like, and a car that you can EASILY do mods to later if you want. (I don't think theres much room under the hood w/ that LT1 Camaro?) If its only a header gasket thats wrong, why hasn't he fixed it? Remember you can put a paint job on anything and add whatever you want for a c/d player/system at anytime.
Get a factory a/c car too! It's expensive to add aftermarket and this is Florida. Do you know someone who does a/c work? maybe they can help you out if whatever you get has lines that leak.

Anyway - thats just my opinion. Check out the thread "If you could do it over again" It may help.