Yeah it sounds like your amp only supports studio levels which is understandable really, can you not just turn up the colour on your television or tweak brightness/contrast etc?
I've tested both Limited/Full (PS3) and Standard/Expanded (360) on my TV and when it's set to receive the correct signal they all look the same to me.
A lot of people tend to prefer the look of Full/Expanded even though their TV doesn't support it, but you do get the black crush as you mentioned because it's not correctly showing.
I'm not sure about 360 but with PS3 on RGB full you actually lose blacker than black and whiter than white, because all it does remap/stretch the limited range (16-235) to 0-255 for monitor support - as far as I know anyway.