First potstill, condenser Q's

[HereComesTrouble]

I'm building a simple potstill based on Samohons Easy Potstill design. My thought was to build a smaller vertical condenser, either a Graham or a Shotgun. I'm having trouble with figuring out what would be comparable or better than a 36" Liebig (1/2" inside 3/4"). When I say better, I mean at knockdown ...I'm using a Bayou Classic SP10 propane burner and a 9 gallon pot with 6 gallon wash.

I've got about 15 feet of coil in my shop thats 1/2" OD and about 3/8 ID. I'm thinking thers no way in hell im gonna get that wrapped to make a Graham inside a 3" tube? I'd love to do a 2" diameter shotgun, but im lost in the comparable sizing, especially length. Building it scares me less than coiling that tubing, I used to do a bunch of jewely smithng and metal work. My guess is to use about a 18" long 2" tube, and have 7 - 3/8" tubes inside? Or 4 a 1/2"? Would 12" be long enough?
My column goes 2" to 90 degree 2", then 2" to 1" reducer. Should it go into the condenser at 1" or should I come doen to 3/4" or less? I'm assuming 2" reducer down to about 1/2" on the way out of the condenser.

Lastly, can i just use garden hose pressure into my condenser?

Thanks!