what next

I'm in the process of buying a 1998 mustang gt and with the mods the previous owner has done I'm not sure where to go next. Heres what's been done so far.
steeda underdrive pulleys, timing adjuster, msd 9mm plug wires, ngk plugs, k&n filter, king cobra clutch, adj. clutch quadrant, firewall adjuster, adj. clutch cable, bassani x-pipes and quiet thunder exhaust, aluminum drive shaft, 3:73 gears, tokiko 5 way adj shocks, h&r super short springs, heavy duty end links, caster/camber plates, strut tower brace, steeda heavy duty sway bar (front and rear), aluminum rack bushings, steeda upper/lower control arms, and all suspension bushing have been replaced with polyurethane ones.
The only thing not really touched is the engine and the only thing I can think to start with would be be some headers and maybe a pi head swap when I get the money. I also have a suspension question, with the work that's already been done to it and it being a coupe should I get sub-frame connectors or would that be a waste of money?

Subframes are never a waste. It sounds like a pretty nice start already.

To spend all the money and not have subframe connectors is a waste of money. Sub-frame connectors OWNZ ALL!!!!! :lol:

What should I expect to pay to get some of those welded on?

You can pick up a set of nice subframes for like $100. Take it to an exhuast shop and talk to the guy, they'll usually take in any minor welding job. I'd say maybe 2 hrs and $100 - $150 labor

Average you should pay about $100 to have em welded on.

That's not too bad, a guy I work with has a welding generator at home, think I might stick with a pro though.

Any body shop should be able to do it the difference is the price.