With your mods (and no cash) I would stick with a stocker...
If you need it done asap, then buy a new one and pay to have it installed.
If you can wait, post a wanted ad, and get one for 1/2 price (shipping included) and then install it yourself. Its hard, but not _that_ hard to install...
http://www.dariusrudis.com/mustang/tko/