Do some searching on here and you'll find a ton of info.
For the OTS tunes, you could run them with the mods you have. Just keep an eye on your temps. I would recommend what stealthfist recommended... Upgraded intercooler and colder plugs.
And I'm surprised that it hasn't been mentioned yet, but do the rear
motor mount. It makes a huge difference and is generally the first thing that should be upgraded on these cars.