If it is to keep, I agree with the others do as you like. If it would be for sale, then I would do some research as to what is popular and sells in your area. In some areas Arabians and their crosses are very popular, in other areas not so much and QH are more popular. I would go with whatever sells best then.
We bred my purebred polish arabian (racing bred) to our racing bred (dash for cash, go man go, jetdeck bred) black/white paint stallion. We got the most awesome tricolor colt ever!! He technically is up for sale, but I would really like to keep him for myself. So I am not trying too hard to sell him!!! 8)