Bluelight doesn't really do these "what do I take to get highest" threads. Mainly because it is of no interest to anyone but you.
They all share a decent amount of cross tolerance so it's a good way to ruin your tolerance. At least in my experience.
Combining them always led to me feeling like I wasn't high at all even when I was obviously wrecked, this happens eventually to everyone I'm sure but combining several different types always seemed to bring that about much more quickly.
Not to mention the drastic increase in how much shit I wasn't remembering. So much...blank.
Of course the best thing to combine benzos with is weed. Mmm.