DBAT makes a drop 8 wood bat. Also there was a tournament in the Nashville area that was advertising -9 and -10 wood bats provided to all teams for play.
The Louisville Slugger pro-lite that is used by MLB players and MILB players is approx -6. This is an ash wood bat. Most Ash is approx -5. The top bat mfrs for the pro's make non-ash wood (maple, birch, elm etc) that ranges from -4 up to a +2 (maybe more not sure).
Anything below a -6 will probably have a very limited life span.
Shamrock Bats will be providing bats for this tournament so please feel free to contact Steve Vogle with Aladame Sports concerning the specs. Each dugout will typically have a 28,29 & 30oz bat for this tournament. You are welcome to bring your own bats as well.