I went with 2" and used the StillDragon element enclosure. Aside from that enclosure only coming in 2", I don't think it really makes a difference.
Since you're going electric, you'll want to add coupler or another TC port for a thermometer. You can and another one for a sight glass or just do a sight glass/temp probe combo. A whirlpool port is also nice to have.
Thanks.. I just didn't want to go 2" and everything ends up being 1.5"... I think I am going with 2 inch as well.. just to make it easier to get things in and out of the fitting.. and thinking as I am typing.. easier to go from 2 to 1.5 than 1.5 to 2...