Check out Black Bear Tunes. Not sure what the web site is but I'm sure you could google it. Basically what they do is they send you a "memory stick" of sorts, you plug it into your vehicle and go drive around. City, hi-way, loaded, unloaded, towing and not towing. The device records what all your parameters/factory computor settings are. You tell them what you want different. Fuel economy, shift points, shift firmness, no fuel economy etc. Send them the memory stick thing, they in turn I believe will send you a hole new ECU, you install it and send them your old one.
I don't run any tuners but from what I've read this system is most comprehensive tune I've ever read about.
I believe Black Bear can tune all makes, , , I found out about it on teh GM-Truck.com web site.