in my opinion blacked out windows would look alot better than pictures on the inside of the cab.
however its not impossible to have interior and sound unit in a day cab, if u cant get the mfu to fit then a servonaut would (with much better sound)... just abit more costly.
that beeing said im very curious to what exactly your budget is on this build?
it will be alot easier for people to tell u what u can and cant do if we know what your willing to spend !!!