Personally I would do the prime as you may change tanks in the future. However the blade if you get the 30in will work just as fine. Its preference at this point. But like anything, it depends on what you are planning to have in the tank.
I keep an AI Prime on a 15 gallon softie tank (mushrooms and zoa's) at 70%, I can't see this light being effective on a 30 gallon. I would suggest the nicrew 100watt for that size. (I'm not familiar with the blade)