Best thing to do is find a "tuner" that will work with you through a mail order and will ask you to datalog and retune your calibration until its tailored to your particular vehicle.
Jet Performance is what's known as "tune in a can". It works or it doesn't.
Meaning; you buy it and they're done with you.
"Too bad, so sad, we might give you a refund if you can get us on the phone."
Jet isn't a bunch or tuners either. Its a company. They buy up the little guys and remarket them as thier own.
For example: tunercat II used to be available for 70 bucks from the developer and it was a wide open obdII reflasher. As many vehicles or as many vins as you wanted; no restrictions (I'm fortunate to have a copy of tunercat II). Once it got popular, Jet made the developer an offer and he took it (big bucks, i would too). Then Jet remarketed it but locked it down to a vin and frigged up lots of other things in the program. It's now know as the Jet Tuner and it's nearly useless. Oh, it's also mega expensive compared to what tunercatII was.Something around 600-700 bucks IIRC.
Jet Performance, I recommend you stay far far away from them.
Another option because you're OBDI is to learn to tune yourself. it's not hard once you get into it. Check out Moates.net. They have everything you need hardware wise to get stared. Check out tunerpro rt for free tuning software. Then check out gearhead-efi.com for a good web forum on tuning.
Cheers