As far as filling with eggs, i cant give you an exact time frame, but you could try shifting the diet of the barbs to live foods (frozen brine shrimp and blood worms work if live food is not an option). This should speed up that process...
As for inducing CONTROLLED spawning, you could isolate the breeding pair in a separate tank (water warmer, toward 80F) and remove the adults once spawning is complete. This is obviously a very very basic rundown of the process, there are plenty of posts with detailed information.
Fry can be fed a variety of fry foods, your lfs should have something suitable in stock (if not, VERY finely crushed flakes often will do the trick). Again, there are many posts here that go into far more detail, just search for them...
Not to take the shortcut in answering your post, i really need to go to bed, but I wanted to point you in the right direction.
