Roll your own tuning?

Abilor

Gentlemen:

I am relatively new here in terms of posting. I face a dilemma: for the first time, my Mazdaspeed 3 is no longer upside down, and after three years of working and tuning it, I am getting ready to let go of it, get a Mazda 5 for my wife and baby, and set about getting a new car for Daddy...

Right now it's down to either a 370z with sport trim at a minimum, or a 2011/12 Mustang GT. I will buy used, and reinvest the difference into mods. I am leaning towards the 370z and want to go whole hog: Intake, HFC/CBE, stiffer mounts, lowering springs, etc. And of course: F/I.

My concern right now though is that I have gotten very used to using a datalogger and Cobb AccessPort with my speed3, and the idea of not using my own tuning software to do a street tune is foreign to me. I read that a lot of you are going to Stillen, GTM, etc., but does a handheld programmer with tuning software similar to the Cobb solution exist for these cars? I know dyno is the way to go for precise advancing of timing, etc., but a good street tune that optimizes AFR, BATs and IATs, EGTs, and most importantly for F/I, knock, is something I'd want to tinker with constantly as I mod, mod, and mod some more.

How are y'all doing this?

Potential 370z enthusiast.