If you've got an SCT dyno tuner near you, I would go that route. While a lot of hype has been made about buying mail-order tuning or chips, the truth is that putting a car on the dyno and measuring the actual air/fuel ratio with good equipment is the only real way to do it. When you change a MAF meter, air intake piping, camshaft, or heads, you really can't accurately predict what the motor needs. You have to measure and analyze, which is done on a dyno. Remember, air/fuel ratio is only half the battle. There's timing requirements, idle airflow and cranking characteristics, and several other tuning issues to consider.
Now if you have a bone stock motor, and wanted to change one simple thing, like fan on/off speed, or injector size, or something like that, then a mail order chip would be fine. But start putting several non-matching parts together, and you quickly lose the ability to mail order tune.
It would be like buying an expensive suit, but instead of having it tailored locally, you just describe to some guy over the phone what you look like, and without using a measuring tape. A guess at best.