Any reason you're set on 500mg? If this is your first cycle you should use less, like 250mg test, along with a bit of dbol, like 20mg/day, and your primo. If you want your hormones to bounce back I would recommend getting some HCG. Two shots per week, 250iu each, a 5000iu bottle will last you 10 weeks. You can delay the HCG until the 2nd or 3rd week, which allows you to time it such that your cycle is finished before the hcg. An AI and some nolva and you're all set. For a lighter cycle why not use aromasin? It's mildly anabolic and is better on your lipids.
Dbol isn't for savages, lol, it's a great compound, and I always felt great on it. It certainly stands out. To give you some context of not needing a lot. I had a training partner way back, decent sized guy, 6'1, 225lbs. One 6 week cycle of dbol, 25-30mg/day and that guy gained 50lbs. Believe me or not, I don't care, and I'm definitely not suggesting you can replicate those results, b/c he had fantastic genetics, was a seasoned athlete, and our training was brutal. But, even myself, my first cycle was just dbol, and I easily gained 25lbs.
I'm also not suggesting a dbol only cycle, and think you have the right idea, but if it were me I'd take less.