Install tip #1: See my post above!
Make sure the radiator has the metal reinforcing tube in both necks. I think you'll only find this in the Behr, and to the best of my knowledge they don't offer a lifetime warranty.
A lifetime warranty isn't going to do you much good when your stuck on the side of the road and everyone's closed and all your car's life blood is running down the gutter and your 100 miles away from home and your cell phone battery just died. (See Murphy's Law)
It's really not worth saving $10 or $20 dollars to get a 2nd rate radiator, especially when you're having it installed at a bargain basement price.
My $.02 worth for free, and free advice is worth every penny you pay for it!