My daily driver is a 2002 GT with similar modifications as yours. Up until about a week ago I had a Stallion 9.5 inch 2800-3200 stall converter along with increased shift points and 3.90:1 gears. (I removed it because I may be selling the car) With this converter you can launch almost like a stick shift and never know it's in there during normal operation. If you just punch it at a traffic light it flashes up to about 5500 and settles instantly back to about 3000-3200 rpm an you are moving! It's a lot of fun.
The Precision Industries Stallion is a high quality piece that, depending on where you buy it will run $700-$800. I put a deep sump pan and a transmission cooler in at the same time. I've driven it at highway speeds for long trips and had no heat problem with it.
I wouldn't mess with anything lower than a 3k. Boss hog has a good one. TCI has very nice one but it will set up back a lot. B&M also makes pretty decent ones. I was going to put the 3k Boss Hog in mine before the auto took a dump.