
Most of the wear items are readily available over the counter at any parts store or rockauto.com. Specialty items like intake parts etc you'll have to look to specialty shops like MSA (zcarparts.com), VB (blackdragonauto.com), for Nissan parts you cant beat the prices at courtesy (courtesyparts.com).
The body/chassis are the number one concerns, especially here in KY, at least in Louisville, we use salt and lots of it! Not a lot is available in the way of replacement metal and patch panels. Mechanically once you fix the sins of past owners they are pretty trouble free with some basic maintenance. sure hoses and belts will age out but replacements are readily available.