Background; I'm currently running a system which at peak runs with about 15 million messages per hour using ActiveMQ, with several producers and consumers on the same topic. Apart from speed, not had any issues with it.
ActiveMQ or ActiveMQ Apollo? Definitely give Apollo and try if you haven't, it's incredibly easy to drop it and requires very little configuration.
I'm processing similar peak levels with Apollo, and so far have been amazed at how well it handles things.