nice work. what to breed really depends on if your looking to make money or ar just doing it for fun.
on the cash side of things there are very few fish that most shops will buy but i think u just cant go wrong breeding bristlenose, i know shops in my area will buys them and they normaly hate buying local...but i would also advitise on websites for a doller or two more then the shops will give u as well.
on the fun side well thats a matter of oppinion really im trying kribs at the moment but when i get more space (and tanks...and rooms in my house) i wanna try oscars,.
good luck keep us posted