The latest official OS release for the 8330 is 22.214.171.124.
The latest beta I think for 8330 is 126.96.36.199/51 (one of those two)
Unfortunately I can't judge if it is safe for you to upgrade to a beta version, think about whether the possibility of running beta software (which has the potential to have a security leak somewhere, or any form of instability towards applications your BES may rely on for business) can provide a threat to the daily operations of your system.
I put 188.8.131.52 on mine not too long ago, quickly downgraded since I saw no vast improvement to the system, with the exception of the Google Search bar in the browser and little things like that. But no way in hell would I have put beta software through a BES that I was administering.
"He that hath no sword, let him sell his garment and buy one."
Jesus, Luke 22:36
"The deadliest weapon in the world is a Marine and his rifle."
Gen. John Pershing, U.S. Army