Do you know this guy? You seem to have inside info. State your aim, and then let us tell this kid how to make his 8 gallon work for him untill he buys another tank.....
They're having a sale at my lfs on 20-longs for $8. As someone else said you should get them a 29 but a 20 gallon long would be the absolute minimum you would want and they're cheap. Do the right thing. Does that biorb have any filtration?
*edit* Mbunafishkeeper, is this a friend of yours? I didn't notice at first but he seems to be directing the thread to you with your name and a couple of confused smileys in the top post. Sorry I wasn't dogging him. Just letting him know whazzup.