Depends what you want to do with the tank and how much work/maintenance you are prepared to do.
Personally I think that 110W will be enough for anything so long as it shines on all areas of the tank.
I want like a riverbed look...i have co2 already . Its not gonna be a fully planted tank...its gonna have a bunch of driftwood(christmas moss and riccia on rocks and driftwood) and an open area for the fish to swim
It can also depend on the fixture. You could opt for the higher output and hold it back(i.e. not run all lights) then you always have the ability to go for more at a later point if you so desire.