Ive done convicts before and to be honest it was fun, but really I just want to breed a fish that I really enjoy keeping. Convicts are ok, but they lost their appeal to me some what quickly. Jacks maybe something I would be interested in as well. I really wish I could do a Mota pair, but I worry that would also be a bit to big for my tank. Would Jacks outgrow the 75g once they were larger and still breeding? Also if I plan to upgrade eventually is there any reason not to do Green Terrors in the 75g for a while? Honestly that is what I would really like to do the most.