Some great replys!
I checked at HD today and found that 3/4" cpvc conduit is only $.30 more a stick so as per your good advice I'll spend the whopping extra $6 and make it easier to pull the wires.
I also found some 8-2 wg romex on Craigslist so I plan to run that from the panel till I get it out of the house.
If I'm going to be stupid, dangerous and illegal It'll be my rear end that's at risk and not my poor tennants'.
Gonna be great sitting there in my sneakers and a sweatshirt, sipping coffee and listening to the radio instead of freezing my toenails off in an open stand like I've done for the last 47 years. Getting soft I guess.
I'll post some photos of my shack when I get closer to having it done.
Meanwhile, just to keep this tractor (or tool) related here's a pic of a 3 point trencher I built about 10 years ago. I think I will add a small wing on each side of blade to open the trench a little wider. Make it easier to drop the conduit in.
Many thanks to all.