i would suggest you to apply the RB411 + dbii F50-pro, we have more than 150 unit's on air, it's work perfectly to us.
but one thing is, you need to add on the dbii "safe surge pro" surge protector in the enclosure, to make it more safety, you should apply the L-com high power POE surge protector before the bridge.
remember to ground all of it as well, i will very sure, you will like this setup and problem free.