Steph Welcome to the Board!
A few thoughts from me:
1) The years that you are looking at have less than spectacular braking capabilities;
2) Power is definately there - plenty of torque ~300 from the factory. And, increasing HP and TQ is a fairly easy thing to do on these cars. They respond very well to modifications.
3) Handling is average - again though, modifications are easy with Steeda, Kenny Brown, etc. all having great suspension packages that you can purchase that will make the big $$$ sports cars look down right silly;
4) Working on a 5.0 Mustang is very easy. I knew nothing about cars before purchasing my Mustang. But, in the past six years I have done head swaps, tranny installs, put in a new clutch, exhaust work, engine work, etc.;
5) As for learning all of this, well the best way is to frequent this Board, read 5.0 and Muscle Mustangs and Fast Fords (two popular Mustang magazinges), and to work on your own Stang.
Good luck with your decision, and again, welcome!
E
------------------
1991 5.0 LX Coupe - 38,000 miles
13.17 @ 106.14 mph w/ 2.138 60'