I would say.... put in the BIGGEST thing in there that you can afford (or that can fit).
I would say this... whenever you go to friend's place / show room and see those HUGE tvs...
you would say... "Wow !! that's a big one !!!..."
but you would never say... "Wow !!! that's TOO BIG !!!..." lol....
So, depends on your budget and space avavilable, put in the biggest you can afford to put there.
I have a 110 in screen with front projector installed a few yrs ago...
I love it !! I got that movie feel !!! my friends love it too....

only thing with front projector is you need to keep the room dark.
So, if you plan on all lights on, mame cab shining, pinball machine on and light flashing,
and some other people reading magazines... etc.
Then maybe front projector is not for you...
but I believe front projector is cheapest in terms of $$ and size ratio...
whatever you go with, go with the biggest...
