Ask HN: Best method to track/monitor beta testers?

Hi,

I've been working on a project for the last 4 months (video streaming/web app) and we are coming very close to the point where we're looking for beta testers to do a few rounds of invite-only testing. Feedback is going to be very important over the next few months and I looking for a great ticketing system, place to log issues or make suggestions...I've been looking at customizing a few simple Wordpress systems as well as services like ticksy.

Any recommendations on a good platform to do this or some best practices in monitoring early beta testing?