Goto radiantcompany.com. you can get a free est. it will ask size, how many doors ,2x4 2x6 walls, insulation in walls and ceiling stuff like that. Used them 3 times very helpful.
Dont by the polaris, got one sittin next to the shop right know, lots of problems. Switched to a tankless,bills droped and never had a problem in 2 years.
pex radiant w /propane tankless water heater. Just finished a 40x60 with 16' ceiling. Works great!!! Also have tankless n/G heater in my barn with plex floor, the only way to go!!!!