There is a high possibility that they will cross breed, and it can be difficult to breed multiple species in one tank. They will expend most of their energy competing over all the females and aggression can be higher. And when it comes time to try and catch a holding female, you will have to tear the tank down. You may want to consider a male only tank, where you will have lots of color and lots of show type specimens, instead of half your fish being a nice battleship grey. And remember it is the female who picks the male.
If your interest is really set on breeding, then I would suggest a larger group of just one species. And then you could do a group of Labs with them, or Cynotilapia sp. also mix well with hap types.
You tank is a great size, and haps will fill it nicely.