Rim's right, the deca might be a little too high. You can run 600mg/wk but if you do, you would probably want to up the test...deca usually works better when test is higher. Also, I've run 600mg/wk of deca a few times, and for some reason when I do, I tend to get nose bleeds. Not all the time, but it happens.
As far as what else to add, you're right, there's a million things you could do here. I'm not a huge fan of orals, but that's your call. As for adding in another injectable AAS, you'd need to give us some idea of what you're thinking about...because like you said, there is a ton of stuff out there.
Finally, bulking cycles are best left very simple IMO...no need for too many AAS compounds. However, added in goodies like GHG or IGF-1 would serve you greatly, especially on a 20wk cycle.