Jeff,
the sureflo works great with the varistream. If you are running one hose from it, get 75psi it is fine. I have had mine nearly year and half, still going strong, not even a hint of problems yet.
I think the Varistream works best with 75psi sureflo. I wouldn't be surprised if that is what they road tested it with!
Pj
I don't talk rubbish, I cleanitoff!