If you're planning to add a turbo setup later on, you have to build the engine for it - ie: lower compression. 8.5-9.0 is a good number unless you plan on running E-85. But that low of compression would obviously suck N/A. It has to be a commitment, not an "I'll add it later" deal.
My recommendation is: you should only add a custom turbo setup if you have owned a turbo car before and modified it. Unless you have the guidance of a turbo expert. There are a lot of details that need to be in place to have a successful (and safe) setup.
97 T-Bird LX 4.6 - 68k miles
94 Supra TT Auto - street/strip car
04 Crown Vic Police Interceptor - Brenda's car
95 T-Bird LX 4.6 - fully optioned, owned 15 years
96 Cougar XR-7 4.6- Brenda's car, owned 11 years
88 T-Bird 3.8 - first T-Bird, owned 5 years