Firefly to both normals lemonblast pewter mystic
Bumblebee to pastel spotnose yellowbelly pinstripe

I'd do it that way so you get the most out of your normals by hopefully getting fireflies and fires, then your two genes in hope of 3 and 4 gene fires. The bee still gets reasonable action with decent results can get some spinnerblasts, killer bees, bumblebellys etc. my other option if i was you would be

Bumblebee to 2 normals spotnose pinstripe
Firefly to everything else

Only because I think Fires are such a nice morph mixed with anything else and from a business side more valuable too