Definitely stay away from copper covered aluminum. 1/0 is big heavy cable, and hard to work with. I used 2 on the last 1500w I installed, thou I was sent 2/0 for one color. I used the 2/0 but it was a pain to thread through the truck to where the inverter was installed.
The charts I looked at say 4 guage 100 amp 30 feet. So 2 should be enough safety margin.
I still need to wire my 1k, I haven't decided the best place yet