Most people would advise against running Superdrol for your first cycle. This is what I would do in your situation, I am not the most experienced guy on this board by any means (so take it for what it's worth), however i've followed quite a few logs and have some experience with Superdrol, solid gains.
I realized I forgot to post the log I mentioned, this is it
http://anabolicminds.com/forum/steroids/90575-revolted-my-epi.html Solid progress and similar in terms of your goals.
In your situation, with June and July approaching, why not run the cycle mentioned above? Or you can run Havoc with Furazadrol/Winadrol for solid gains and a decent lean look, this will probably better expose your abs (given you are in that kind of shape).
Save the Superdrol for the winter when you can eat without worrying about showing off abs. Even at your size, SD doses seem a bit high for your experience level. IMO 10/20/20 should work fine, if you choose to run another week its up to you but I would keep it at 20 being your first SD cycle (I realize you are a big guy).
Ultimately it is your decision.