I have always believed that fish with big mouths, especially including catfish, will eat any smaller fish they can find. Is that true of petricola? (I keep thinking PepsiCola, for some reason.)
Today I found a nice tank about 90 miles away, at a great price, and my wife says, "let's sleep on it first". The tank, unfortunately has a plastic rim, but, as far as I can tell, it doesn't have a cross brace, so it may be no problem to remove the rim. It is a Craigslist tank, so some more email traffic to get a better feel for it may be necessary too. And, a visit to a couple of LFS looking for rimless tanks is in order too.