Gary dosnt carry out remaps, but he does do piggybacks and tuning He did mine (If you speak to him, tell him Mark says Hi and I will see him next week!)
Am sure he can get the mongoose in, but as an alternative there is a lovely 5zigen one at Envy!
Do you know what your power is at the moment? If not, get that on the dyno first so then you can get an idea of gains! Dont think anyone can really give you an idea untill you have had it dynoed..
Did he suggest doing manifolds, decats and then full mongoose zorst? What about the plenum?