Sounds like a good, hard hitting cycle. Not much to suggest to be honest. It looks you have done your homework, bro! If you like the GP sust, I think you could run it through the whole cycle with no problem. I'm a big fan of their Sust 270. I'm also a big fan of their Prima 100. The dbol is very good too. Think you should have a great run brother. If you wanted to opt for more mass gains, you could consider using EQ instread of primo. Primo is good for cutting and I get some good strength out of it, but I think EQ is good better for adding mass. Good endurance, fullness and increased vascularity. You could run that at 5-600mg for 16 wks and make good, steady progress through the whole run, espeically with your insulin plan. Throw in some GH and maybe IGF and you'd have all your bases covered!
Oh and on the note if slin, I didn't mention before, be careful with it. Obviously you know it can be dangerous. But understand that it is not going to help an Endo. If you tend to get fat, slin will only make you MUCH fatter!