Just finish out what you're doing, then reevaluate. Worst thing you can do is get some new equipment, then retool your entire purpose: Increasing raw strength. Even the biggest benchers can still press 500 completely raw. Skarhead, a friend, has said lately all he's been doing is shirted work, and it really hurt his pressing off the chest. Even with speed work in there, it's a totally different animal. As you know, the shirt does the first part for you.
Westside doesn't really do any shirt work at all unless you're getting used to it. It's just a matter of finding a comfort level and your groove. But as for actual shirt work, they don't do it because it's really the same thing as floor presses with a 120 lbs of chains, or 3-4 board presses, ect.
I would stick to your raw strength. Then reevaluate adding in equipment here and there IMHO.