I also run a Vast tune, I've been involved in whiteblock modification for the best part of 16yrs, have blown engine's, wreaked gearboxes, snapped driveshafts just to name some dilemmas, during that time I have evolved through countless "tuners" in the UK and even tuned my own when turbotuner ECU's became a thing, no one has got close to the seamless way Aaron tuned my car, yes it took a total of 10 revisions with a little tweaking each time but the end results are spot on. Yes he's a busy man and takes a few days to respond sometimes but go with it,
Also the standard 16t is fine with a better exhaust housing, you really wouldn't notice that much of a difference once changing wheels etc, again it all depends on budget, if you have $$$ to throw at it go for gold, if you want a reasonably quick point and squirt car that's reliable save yourself a couple of grand and keep it simple and reliable, it's much more fun knowing you can trash the car and it's not pushing the limits too far.