I agree with the above poster and get both Mojave and Albino females (as well as your pastel) and use your Spider male on them when they are ready. It'll end up being the same money (maybe even cheaper) because you wouldn't have to buy the Albino and Lesser males. It will take an extra season but you will have a lot more to work with.

Your Pastel will yeild the Bee's you want. Your Mojave and Spider will produce at the best Mojave Spiders, which you can then breed a male back to the Mojave and get the BEL's you want. (If you don't like the purple head BEL's, get a Lesser/Butter female instead of a Mojave) The Spider and Albino pairing will yeild at best Spiders het Albino. Breed a male back to the Albino female and get at best Albinos as well as Spider Albinos.

Win/Win in my opinion!

But if I HAD to choose just one, I would go with the BEL project.