I've owned 5 fox body Mustangs/Capris total - still own 2 and am about to pick up another GT to build into a show car. I've been into these since the mid 80s and can offer a lot of technical support and advise on aftermarket parts for these cars. Now these cars are by no means a rarity at a cruise night but if you want to go this direction, you could go with an 85-86 Mustang. The 79-86 fox bodies have the sunk-in headlights or are called the 4-eye cars. These cars are rarer compared to the 87-93 aeronose cars you see all the time. of all the 79-93 Mustangs, notchbacks or coupes is the most desirable body style due to it being lighter and structurally tighter due to it not having the hatchback door. They also look tougher in my opinion. ANyways, let me know if anybody needs some info or suggestions.
Here's a pic of my 85 notch that's getting a huge makeover...
Also, it's funny you mention the 5.0 and Monte SS in the same thread - one of the guys I work with has a very sweet 1984 Monte SS g-machine - 330 hp crate motor, 700R4, 17" TT2s, Baer brakes, lowered suspension. I was following him back to town a couple days ago in my 1988 GT (this is my 99% stock daily driver, 102k miles - stock except for 2.5" catback exhaust, that's it!) and he layed into it thinkin' he was gonna leave me totally in the dust. Surprisingly to him AND me I was all over his tail and he let off as I was reaching 5000 rpms in 3rd. With a stock 3.08 gear and 225 hp I could keep up with the heavy Monte and 330 hp! He wasn't real happy about that. A 3.73 gear, headers and off-road h-pipe and I think i could take him. Something to think about when picking a car or platform to start with. A 5.0 is actually a good, cheap, and fast starting point if you find a good deal.
John