honestly, put the gear away for a little while. if your goal is strength and strength only its one thing.. but if you want to truely look good then 20% bf is TOO HIGH. you will put on more bf on cycle eating so much along with muscle, just the way it works. so drop your bf down to 15%, then you can start gear. until you get that bf down you will be dissapointed in your results.
and also you haven't been working out for too long but definately seems like you have done your research.. KEEP researching.. like i told another guy, I thought I knew a lot also when i did my first cycle, and I had a very good cycle.. but it could of been better had i waited a little longer and kept gaining knowledge
to ansewr your question if you eat properly you can expect to get 20 pounds easy but everyone is different. at your bf you need to do cardio also.. i was 9% bf when i did my first cycle and blew up to 15% and family members were actually calling me fat so keep that in mind even though i added 50 pounds to my bench press. so i would work your ass off for 6 months, THEN hop on the gear.. you will have much better results.
BOTTOM LINE is if you are on here asking questions then you need to keep researching. until you get to a point where you know everything about both your cycle AND PCT then HOLD OFF. your PCT you mentioned to open the thread is poor (as was mine when i did my first cycle and i wish i had waited) listen to RADAR on that or PM needto, he will help you lineup a good PCT.. them and nelson have helped me immensley lineup a good PCT and I even feel like I want to wait before i start my 2nd cycle until I really build up my body and prepare it for a rigorous 3 months.