The cooling mod is definitely the important one. Some of the ones that I really like are:
a) Marty Tune;
b) 4.10 Ford Performance Gears;
c) K&N CAI
d) Stainless Works headers;
e) Metco Control Arms and Watts link;
f) Addco front and rear sway bars;
g) TCE Performance Stainless Brake Hose Kit;
h) And of course, Boost!
You may also want to take a look at a set of new Timing Chain Guides / Tensioners when the time comes. This thread will help you:
https://www.mercurymarauder.net/for...ist-to-do-your-Timing-Chain-Guides-Tensioners
Many of us do the mods over time, so don't feel you have to do it all at once. Once the mod bug hits, it's hard to stop.
You'll find that Marty, Zack, Jerry and Jim (Fastblackmerc) thoroughly know these cars.
You mentioned that you're in Westchester. If you plan to drive year-round, you will want to wash it often to keep it clean, otherwise the rust will creep up on the fenders and underneath. It can happen in less than two years and it's a never-ending battle.