Several issues at once there.
To start with your last point, disposing of fry can be a challenge unless they're rare or very popular. Very popular ones tend to be bred frequently so you won't sell them for a lot, rare ones are rare for a reason, so you either have initial outlay to buy the parents or there's a knack to breeding them that you'll need to master.
To give you an example, I have a tank full of Thoricthys Ellioti. I've shifted a few but still have a tank out of action with 30+ fish in it. One local shop is vaguely interested but they've not exactly snatched my hand off. Several others gave an outright no and several offered to take them off my hands for nothing.
My best advice is to start at the selling end and see what you'll be able to shift, check local shop policies and look at whether you're willing to get into shipping. Once you've found something eye catching that you think you can see a route to sell, and can find a source of, sort a set to breed it. Doesn't mean that you will but does mean that you wont go through heartache trying to shift them.
Personally I suspect you're onto a good line with dwarf cichlids, but make sure you breed from good parents if you want good prices.
