I would appreciate some general pointers and opinions regarding which of the two messaging systems is
I use ActiveMq quite heavily in my day job, and rate it very highly for most of the points you raised. I especially rely in the JMX admin console, it's top class.
I have also been keeping a close eye on HornetQ, and may one day add support for that too. From what I can see HornetQ is a bit lighter weight, and has some really nice NIO optimisations, which should make it fly. But lacks some of the enterprise integration features offered by ActiveMQ, and possibly some of the admin features. However, from what I can see the HornetQ team is working hard to fill in the gaps.
I don't think you could do wrong with either choice in my opinion. Try them both out and see which feels better.