Need Hell

Need Help

I bought a 2006 mustang gt deluxe back in august. I owe about 4k on it give or take. it has 152,533 miles on it. Once I pay it off I want to make it a lot faster than it is because i’ve kinda gotten bored of it. First thing i’m doing is an slp loud mouth axle back, then I want to go twin turbo and there’s a place near me that will twin turbo mustangs if you buy their turbos. What supporting mods do I need? Is there any way to make it reliable and fast? Should I go 1 big 107mm turbo or 2 medium twins (50-60mm)? How much should I expect it to cost after supporting mods? I’m starting to save up now from scratch. Any advice or help would be appreciated!!!