The fish will get along if their needs are met.
Meeting their needs is the hard part. They will require a lot of food, places to feel safe and room to swim. As they grow (and they will grow fast), they will get more agressive because their needs aren't being met anymore and you will have to move them on to bigger homes. You must be willing to do the best thing for the fish to give them a part time home. If you aren't willing to give them away go a bigger home (for free if necessary), then don't get them and choose a fish that will live it's entire life in your tank. The fish's needs must come first.