Hey Brother,
My guess is that your gearing will be altered enough to get you into high 13s with the shorter tires.
No clue what class it would be in, but I would think you'd just be looking at bracket racing (to get some "tree"time).
You don't need to worry about a roll bar until you hit mid 11s.
And hey, maybe I'll run into ya there sometime!
Good luck, and have fun!