Here a few pics of my 135 gallon planted tank. This tank used to be a reef tank and I converted it over to freshwater about 6 or 7 months ago. It's currently lit by flourescent bulbs but i'm going to swapping that out this week with two 175w halides.
You are probably going to need a ton more plants and pressurized CO2 if you add a lot more light.
IMO, that plant mass will not support 350 watts especially without a carbon source.