I am going to run 3/4" PEX from my water meter to the manifolds. In the Zurn installation guide they suggest running 3/8" PEX when possible as you will get your hot water faster than if you ran 1/2". My local home center does not stock rolls of 3/8", they just have it in 5' lengths. Should I try to find it somewhere else in 3/8" or just run the 1/2"? This is going to be my first time using PEX, any quick suggestions?