Is it OK to do a cut cycle after a "bulk"? Absolutely, people do it all the time. Not necessarily how you have it laid out but yes. What people will do and what I would recommend, is switch out compounds after while and at the same time alter the diet.
If you are 6 foot and 180 and single digit bodyfat NOW, you most likely will not go double digits from a cycle of test and npp (or any cycle for that matter) unless your diet consists of nothing but Pizza Hut and McDonalds.
In fact there is a couple of dudes I know that are naturally lean, metabolic freaks of nature, that have to consume a whole pizza at night after training to not LOSE weight.
So my advice first off is not to worry about DNP, you won't need anything that drastic. Instead, run your cycle of test and NPP, but run it for for 12 weeks. And trust me, a lean dude like you(youre not fibbing are you?) is only going to get leaner as the cycle goes on, even in a calorie surplus. You start adding muscle and your metabolism is only going to get stronger. IF at some point you feel like you are getting too much weight gain/fat whatever, just alter your diet. No need to add DNP. Anavar to be totally honest could help, so by all means if that's what you want to do add anavar, but it's not necessary.
A true "cutting" cycle would be some low dose test p, trenbolone ace, and winstrol or masteron, or both. Keep in mind though that while the aforementioned compounds can help in a cut, the primary determinate(90% or better) is going to be your diet.
Also, going forward it would help us out a lot if you included some pictures so we can see what you look like, and include info about your diet. You also didn't mention in your first post that this was your first cycle...