right on. 8 8 gauge then.
As for the solder vs mechanical.. I differ in opinion because correctly soldered connections make better connection than mechanical connections can. You are the only person I've ever had tell me their soldered connections lost them conductivity.
This is not the place for this discussion though so, I'll leave it at that.
Good luck with your sale. I think it is gorgeous cable. Do you have a picture of the install? I think that much cable had to be impressive installed.