Yeah severums will need a 50 gallon at least, they are also very hard to pair up. Also for your grow out tanks, I think a 29 gallon is fine. Fry don't get lost as easily as you think, and they will outgrow a 10 gallon very fast.
@thelaw Maybe you should start a new thread to condense your 4 threads. You seem very interested in keeping cichlids and that's great! Maybe start a single thread where we can all suggest possible stocking options and tank sizes
Also, I hope you're not thinking about breeding convicts for profit! haha the most you can get for a spawn is maybe a bottle of food or water conditioner or something like that