I started a system in May 2012 but did it with Rainbow Trout. When those did not work out I switched to Brown Bullhead. I have 25 fish using a 200 gallon grow bed. This is my system:
http://www.backyardaquaponics.com/forum/viewtopic.php?f=18&t=13785
I have only grown the fish for two months at the most (I did have 3 starting in May 2012 but most were added mid-summer) so I haven't harvested them and I plan to overwinter them and let them hibernate. I plan to grow them again starting at the end of April 2013. They were small when they went into the system. Here is an example:
They are very hardy, but they can be abusive and non-tolerant of other fish species. I've had them attack other fish I've tried to put in the system. I've read this isn't as much of a problem if you introduce fish that are larger than the Brown Bullhead. If you have other questions, please let me know. I may or may not know the answer.