I'd guess SanPablo on the red fleshed one. No clue on the other.
Close. It's Fernandez, and was my first time finally getting to try it.
The pulp surrounding the seeds was the best tasting I've come across--was like a mix of alpine red strawberry, RL papaya and Ruby Supreme Guava all in one. Really hard to describe the joy entering into your mouth with such complex flavors. The pulp near to the rind was a little gritty and not as flavorful, but the seed pulp more than made up for it.
The cuban white wasn't as full flavored as the Fernandez, but the flavor was sugary and similar to an orange sherbet melon, and the flavor was consistent throughout the seed and rind pulp. Much more gritty near the pulp than the red.
I highly recommend both of these custards.