Vasoblitz is going to be a little more comprehensive since it contains solid doses of Citrulline and Betaine.
Noxygen is a solid choice if you want Glycerol + Nitrates and probably a bit cheaper.
I don't think you can go wrong with either, but if you already have a pre-workout that contains Citrulline that you use and/or you are going to stack it I'd opt Noxygen, if you want more of a comprehensive pre that you'd maybe only have to add stims based on an as needed I'd probably opt Vasoblitz.