#3+4 you can purchase pre made radiant manifolds that will hook directly to your radiant loops,get the ones with valves and flow meters built in to adjust flow to each loop, lets see parts? 30 pound relief valve-1, pressure guage-1, drains to add anti freeze-2, #30 Extrol pressure tank -1, and air elimination device, ( I like the Spirovent ) your expansion tank screws right into the bottom of the Spirovent, radiant heat mixing valve-1, tees and ball valves, try not to put any more elbows than needed and have fun!