if you have a nice pastel male and want to use it to produce bumble bees, i would buy a female bumble bee or killer bee (= super pastel spider)

no, really, bumble bees are cheap enough. and for breeding, when looking for a female, depending on your budget, i would look for something more than just a single-gene spider. with the pastel male, any female with spider in it will give you chances to produce bumble bees, or bumble bees with extra genes. so you could for example buy a lesser spider female and eventually hatch out your own bumble bee.

about the leopard male: how many females do you have? you should buy females first, and males only if the females are getting up to breeding size and you have enough females.