Hi should be good for a couple of years they dont get as big as some of the other big cats! the biggets one I have seen personally was little over 20 inchs and was 6 years old in a 500 gal tank!
Its one of the fish I am looking to aquire, if you have a chance to get one I would go for it!!!
I just got one for a little more than that, but I wanted it really bad. I just got it yesterday, and it looks like it has a small amount of ich. I usually treat ich with salt and heat, but aren't scaleless fish sensitive to this?