That's a good amount of test to start, and with the dbol, you should hit that 30 lbs gain mark pretty easily. Diet will probably dictate a lot of how much you gain and keep regardless of anti-e's and PCT. Yes, you might be prone to gyno. I would suggest working with the estrogen because you need that for your gains, believe it or not. Basically, you take clomid (not nolva, that just blocks receptors) during the cycle so the body doesn't have a need to aromatize in the first place. It can be a little bit of a trick to find the right dosage to balance the test-estrogen equation, but once you do, you have three benefits: 1) test stays high to build muscle with less conversion to estrogen, 2) the clomid blocks receptors from real estrogen so there is an anti-e effect, and 3) FSH and LH don't drop off so much so you aren't as shut down at the end of the cycle. PCT then is far more mild, and you're back to normal faster. This is pretty much a new school of thought, working with the compounds and the feedback cycles of the body. If you find that your body converts to estrogen much too readily, then you'd want to bring an anti-e into the scene.
If you also add in IGF to the mix of your first cycle, at least 50-100mcg per day, I would expect you'd gain a little more size plus keeping most of your gains. Again, diet will be crucial.