The Nash-Healey was sold as a 2 seat hardtop and a 2 seat roadster. All models got a 4.1 liter straight 6 cylinder engine, which provided more than enough power to get these car down the road faster than just about any other car around. These cars earned their reputation as fast cars at the track, including wins at the 24 Hours of Le Mans.
These cars were rare, even by modern standards. Only 500 of them were made combined in 1951, 1952, 1953, and 1954. They competed in the same market as the Kaiser Darrin, Chevrolet Corvette (the original 1953 model), and the Ford Thunderbird in 1955. All of these cars had similar bodies, although the Nash had better power numbers than the others.
These cars were rare enough when they were new, and considering that they stopped making them over 50 years ago they aren't getting any more common. You'll have to search for quite some time before you'll find a Nash-Healey, but I can make some suggestions. First of all, use eBay. If you can't find one in new condition, you might be able to find a decent project car to work on. Finding parts will also involve using eBay, along with swap meets and the knowledge of car clubs.