RE: arrow weight v. speed for penetration
I think penetration and KE is a non-issue with your setup, unless your hunting really big-game. More important is your broadhead flight and what happens in wind or when hitting a twig. In my opinion the extra 25 grains is very helpful to increase your F.O.C. for a better flying hunting arrow. I find that 125-140 grain heads on a good stiff carbon arrow, result in some pretty darn good broadhead flight. Lighten up on the tip weight and things get more critical for spine or shooting in wind.
At the ranges most of us shoot while hunting, speed is probably the least important component of success.