Welcome! You found the right place. This is the friendliest most helpful group of its kind on the internet. Educating yourself about these cars before you buy is the best way to find the right car for you and minimize unrealistic expectations that could later sour the experience.
Remember, your buying a ~30 year old car. There will be challenges with parts availability and repairs. Your best off to learn the car and do your own work, if your capable. Even low mile cars can have major issues from simply sitting. Also be aware your dealing with 1st generation automotive computer electronics that are, in many cases, very unlike today's electronics. Generally, within this community, parts availability is not a problem. Especially with supporting vendors like JerrysGaskets.com. Don't expect to find many LT5 specific parts from the normal sources.
You ask about comparing the ZR-1 to a C5 Z06 and such. Simply put there really is no comparison. The C5 chassis is more refined. But the C4 will handle as well if not better depending on what you do with it. The C4 is a more raw, visceral even analog driving experience. Squeaks and rattles included. The LT5 and the LS1/6 could not be more different. LS motors need no explanation. The LT5 is more European in nature with a ~7200 rpm redline and most of its power (hp & torque) well above 4000 rpm. Don't look for the LT5 to have the low end torque of an LS. Its simply a different experience.
In any case, poke around here, ask questions and like has been said see if you can find a local owner and drive one.
H
