You have a nice looking pair of snakes but I don't think the two will work well together. If you really want to breed snakes- pick up another adult Corn or Mexican Black King. You'll pay more for an adult, but you'll also end up with offspring people might want to buy. I've seen some King/Corn hybrids that looked quite pretty (and I've seen some unattractive ones too!)- but they were different varieties of kings that allowed some of the corn pattern or banded king's pattern to show through. I think you'd end up with a dark, muddy looking sort of corn patterned clutch of hatchlings that would probably want to eat each other with your current match up. With pretty normal corns going for $10-25 a piece, I can't see too much of a market for less attractive mixed pet snakes. Just an opinion. Patience Grasshopper! 
Lora