The only way you're gonna see what's behind the ceiling is to have a look. You would need to consult a professional to have him assess whether or not what you have in mind is doable. You have to figure, that if there was a 10' ceiling there before, why can't it be put back that way? At the same time, you have to wonder why the ceiling was lowered to 8' to begin with. (There are more than the obvious reasons.)
It's possible the ceiling was lowered because the previous owner ran out of $$$ to 'finish' a 10' ceiling. That could mean that the walls ABOVE the 8' mark aren't insulated. Or, the 8' ceiling can be hiding something.
Other than that, see what others have to say. My best to ya and hope this helps.