Boring, decking and align honing a block are not supercharged, normally aspirated, or fuel-specific skill sets. They are simply machine shop practices that are performed on any number and manufacture of engines that are processed through the shop in any given period of time. Same thing for cylinder heads and to a lesser extent valve jobs. Porting and valve jobs can have provider-specific benefits, but not so much for day in day out routine machine work. Pick a reputable shop near you to do the work and save yourself time and money shipping out and back.
The real horsepower that an engine produces is much more closely related to camshaft(s) selection and phasing, cylinder head selection and porting, supercharger selection and operation, and most importantly tuning. If you want to make a big difference in your engine's performance get an aftermarket EFI system and learn how to tune your engine — yourself.