20mg/day of nolvadex will help prevent gyno during your cycle but it will not reduce the amount of estrogen in your system and it will not combat bloat.
If you use an aromatase inhibitor (AI) you can keep your estrogen level low and eliminate the need for nolvadex. For your cycle aromasin, arimidex, or AIFM would be good AI's. Letrozole is probably too strong for what you're planning.