2001 Tahoe 5.3 136k Service engine soon

I'm looking for a reputable OBD II to scan this with. I'm keeping the Tahoe, I've had it since day one. But the codes are going to be coming more frequently.

Anyone know of a good code scanner for this tahoe? Yes I know i can go to autozone or where ever borrow theirs and scan it. I'd prefer not to have to trouble shoot in the parking lot of an autozone.

Anywho, the service engine light came on durring my moring seattle coffee run.

I reseated the gas cap.

I am 1/2 through a tank of gas from I can't remember where station. :P I'll look it up on my visa. But this could be my problem.

I am also 136k into milage, Mostly freeway but at this point I am wondering if it is the MAF. Hence my need for a reputable OBD II .

Any Ideas besides these?

http://www.hypertech-inc.com/
Look it over and see what you think. But i know nothing about it. You are on your own on it.
MT

The hyper-tech programers are great if you want to program your ecm, they will scan the codes, but you can purchase an innova scantool, they have 3 different grades starting at about $75 and go up from there.

If you want to go window shopping here is some and some good previews on some of them.
MT
http://www.troublecodes.net/articles/
http://tools.batauto.com/