You would get the same offspring with either one (all the hatchlings would be Pastel, and each egg would have a 50% chance of being Bee).
I think your selection should be based on your future breeding plans. Here are some things to consider:
If you buy a Super Pastel male (and a Spider female), you can breed the Super Pastel male to any Normal female and produce 100% Pastels. That is a powerful male to have! If you have other female morphs, you can breed them all to the Super Pastel and produce some cool snakes right off the bat.
If you buy a female Super Pastel (and a Spider male), you can produce Killerbees (Super Pastel Spider) much quicker. If you produce a male Bee from the above pairing, he might be breedable by the next breeding season (it's also possible that he is not large enough or ready, but depending on when he hatches and what kind of feeder he is, it is possible...). If a male Bee is breedable, you could then breed him back to your female Super Pastel and have a chance at producing Killerbees. If you did the other pairing, it would take a minimum of 2-3 years before you would be able to think of producing Killer Bees because you'd have to raise up the female.
There are advantages and disadvantages to both, so it all depends on what you want to eventually produce.