i think you might definitely be safer going for a bolt-on supercharger.
if the supercharger is puttin the same amount of boost into the motor as the twin turbos, wats it matter which one u put on…
buying a ready made S/C kit > scratch building a turbo kit
any of the major s/c companies has lready done all the legwork for you, you just have to install it. they also know how much boost your engine can handle, and they give you the proper pulley so that you get that amount of boost