I think you need to do a little more RESEARCH before you mod anything. Not meant as a dig, just being honest. . . .
Yes local dyno shops do tuning, but you need to do your homework on them too. . . .
Here's a quick list on what to look for in a tuner:
1. Make sure the shop knows the type of EM you're trying to tune. They should have extensive experience with this type of EM per se. They should also have extensive experience with your particular car.
2. Ask for references, or look for them, they're out there.
3. The shop should have a chasis dynamometer. There are exceptions to this rule, you will know when you have one.
4. They should be busy. If you call them and they say "come in right now!" you might want to make another phone call.
5. THey should use various sensors and analyzers. If they don't use at least a high quality WB, and an OBDII, i would look elsewhere.
6. Time. Make sure they've been doing this a while. Obvious, yes, not always practiced though. . .
7. A owner/tuner. An owner of a business that does the tuning is putting his nuts on the table and should be. An owner that hides behind someone elses mistakes is someone to stay away from.
8. Has winning racing experience. Although not a requirement by any means, but the positive are quiet obvious.
Those who know where this info came from, understand I was not posting to attempt to have credit for anything, only information that I felt should be out there when trying to chose a tuner.