Go with aluminum, it will save you a few bucks. Use a #1urd, this will be 2 #1's and a #2 neutral. Then add a #4u.s.e. to these for your ground. Also may save another buck in the long run to have these in a conduit. this would need to be a minimum of 1 1/2" sch 40. But at well over 100' Life will get much easier with 2" Good luck on things....
