New Combo for friend

[420nitro]

Hey guys, building a new combo for a friend. Need some input specially from you turbo guys. This car already has a Ford nine inch from Currie w/ 31spline axles and Detriot Locker and so on. Also has Wildwood brakes at all four corners. The big question is what to do for a power plant!!!!!
I already plan on and not changing the following:
393-427 CI small block Windsor.
(Scat rotating assembly---4340 forged steel crank, H-beam rods, Ross, or JE Pistons)
TFS-R heads. (with some work )
Super Victor intake

Now the question is what would you put
on a:
1) Tremic Transmission TKO II
or
Dyanmic Racing Transmission w/ TCT Converter

2) Power Adder NOS Bis Shot Plate
or
Turbo (Plus what kind of set-up)
Goal is to complete the entire build for aprox. 20,000 dollars excluding the interior and wheels.
Heres a pic of the beast now.
P.S If we do a turbo, plan on a Dart Block. If NOS, then a Production block will be used but with only a small shot of spray.