honduran red point dithers

I was just thinking, if you can't find a white sajica cichlid yourself, why not create one yourself? So, I got the idea of crossing a platinum HRP (to retain the blue and reds in the hybrid) and a sajica cichlid. The problem here however, is how the genes would cross over. I know the marbled...

I just fried my brain trying to see how these things would work and what I'm going to do... So my initial plan was to get a 20 gallon tank with a marbled honduran red point and some tetras. As for the tetras, I was thinking about getting either Columbian blue and red tetras or long fin serpae...

Need some help deciding on whether I should get serpae or columbian tetras as dithers for a marbled hrp. I like them both equally. (quite literally, they're both pretty much the same, only difference being appearance, and serpae tetras are a little hardier.)