radiant heat

the floor is not poured yet and the outdoor wood boiler is installed and hooked to my house, main line is ran into the barn (pole barn) heated section will be 40 x 50 so i don't want to but a furnace in the corner and be cold at the other. 12' ceilings so all my heat will end up there anyway. thats why i want to start with heat at the floor. only cost is going to be the insulation and pex tubing so i was looking for input on that.