I would focus on figuring out what you want to breed this year, and worry about the rest as it gets closer. Odds are that you will acquire more things, become interested in different things, etc., and change any plans you make anyway. Or else a breeding won't take, and it will put you a year behind and then you can't use that female for the next project she was slated for, or...

Anyway, it is still good to plan your breedings based on where you think you'd like to end up in a few years. Since you want killerbees, I'd focus on producing bees. That means crossing a pastel with a spider.

But it sounds to me like that isn't an option for you yet because the pastel female isn't big enough yet. So it is really a question of which male you want to pair with the normal female this year. If I followed correctly, you have a choice of spider or pastel. Which would you prefer? Do you think you'll be selling them all or holding some back for future projects? If you think you'll hold any back, then I'd make my priority whichever one you think you'll need more of in your future projects. Probably pastel, simply because in making spider combos you only need 1 snake carrying the spider gene, but to get the super pastel combos, you need both snakes to carry the pastel gene. If you expect to sell all of the offspring, then maybe spider because they sell for slightly higher prices (but then again, if everyone uses that logic, the market will be flooded with spiders and it won't be true anymore).

I just reread this and realized I've probably set a record for using the most words to say "do whatever you want". Oh well. Hope it helps you somehow.