Is the SX-160 expansion tank overkill for my 550 gallon capacity system? I have a 490 gallon tank in the basement and the EKO 40 plus 300 ft of 1 1/4 pex. Im figuring around 550 gallons give or take. It seems the SX -110 is only 20 bucks cheaper for consideral less capacity. Also I plan to heat my future shop with a water to air heat exchanger 100ft way so that will be a little more water figuring 1inch pex the the shop.