If you don't need to make a lot of tight bends, the Masterkleer is good, inexpensive tubing. I have used it for over a year now. The Tygon R3603 is very good tubing and is more flexible, but costs a lot more.
If you want the 7/16"ID tubing, you want the #5233K44 tubing that has a 3/32" wall, not the #5233K43 tubing that only has a 1/16" wall. Just realize that you have to put the ends in boiling water or something to get them onto 1/2" barbs. I personally use the 1/2"ID 3/4"OD as I don't mind the bulkier tubing and it is a lot easier to get onto barbs.