Full length weld in tubular sub frame connectors are first and foremost the first thing you want. Then you have Upper and lower control arms, caster/camber plates, larger front and rear sway bars, poly bushings, Shocks, Struts. You could lower 1.5-2 inches, but need to determine the tires you want to use, and want application you want the car for. Getting a K-Member is also a possibility. Ballpark? 2-3K depending on brand, what all you buy, and how much of it you do yourself.
If you have a small budget, you should really do the subframe connectors.
I've heard there is an option for an independent rear suspension, i think its off a 93 cobra, don't qoute me, but I think the swap is expensive. I eventually want to run with that, but I just dropped 4K into the motor and rear end last month so I havent crossed that bridge yet. Hope this helps a little. You can find most of what you need at summitracing.com but there are other places as well. I'm suprised you haven't had any responses yet, someone else I'm sure will come along. this site is very useful and helpful. Welcome the site, and good luck.
__________________ I love my Mustang... But my Mustang REALLY loves my credit card! | 
what is a good suspension for my 1990 gt? 
