Personally, I'd splurge for some Liquidex and keep the nolva on hand. 20mg ED could be okay, it really depends on how prone you are to gyno. Have you used that dose successfully before with a cycle like the one you're about to do?
I've heard as little as 5mg of Nolva being an effective preventative on a cycle with approx. 500mg of test and 25mg of Dbol. However, it should be noted that this was not in a gyno prone individual. Nolva seems to keep the bloat away nicely as well.