Shooting position is overrated. A proper 90* counterclockwise tilt of the weapon (clockwise for left-handed shooters) and placing the reactive hand on the genitalia will yield you good results.
I've never had a problem with the stockers right out of your basic run of the mill LPK. Practice til you can't get it wrong and save your money for ammo.
45 rounds? Lol that will be the longest stage ever, because you'll have to wait for every shooter to swap all their caddies to the next guy so he's not tucking shells behind his ears and everywhere else just to have enough ammo. I imagine a lot of people will be loading out of cargo pockets...
I've got a VP9 you can handle at an OKCGC match sometime. Just let me know beforehand and I'll bring it with me. I'm partial to my M&P40L for competitions, though.