Say that I get an older Coupe, obviously I'm going to want an upgrade. What would you recommend for amps, changing the stereo and an alarm system? The best upgrades is my one condition. Then the only puzzle to solve is what I need to do to make sure I can install everything correctly.

do a search lots of ICE. here is one http://www.fiatcoupeclub.org/forum/ubbthreads.php?ubb=showflat&Number=789213#Post789213

more to the point what is your budget?

Agreed, start with how much you want to spend, what kit if any you already have, what types of music you listen to, whether you mind using second hand kit, and what kind of sound you want from the system...