How much power would I need?

Greetings,

Just a quick question regarding PSU I need to power 7 GPUs.

Calculating all TDPs of my components including CPU, SSD, GPU and etc. I get about 1256w total. In that case, how high should I go on PSU w? Would it be sufficient to power them with 1600w? Supernova 1600w G2. It would be about 300w room with 87% load.