There are few of us Outlaw owners here. From my own experience, I would start with the 8" coil. With the hole in the middle I found it easier to pinpoint with than the 10"x12". Plus the 10"x12" is heavier. The 5" coil is very light and works well in very trash areas. My default coil is the 8".
And as mentioned 53Silvers' videos are quite good. Don't be shy in asking questions.
Thank you John; that's good to know. Weight could be a problem at first - I'm sure it will require unused muscles. But nothing will stop me from trying - it's something I've always wanted to do, but it always seemed there were other uses for money. Retired; now it's time to do something I want to do. And I'm a little kid again waiting for Christmas - can't wait for it to get here! LOL