It really depends on what you want to do. I don't think I would breed a pastel boa to a normal female since I believe that is one morph that was more line breed and you might not get a good result from that pairing. If you had something like a hypo or an albino that would give you what you would expect. Hypo is an incomplete dominate morph with boas so half your litter should be hypos and half should be normals and of course breeding an albino to a normal would produce nothing but het albinos.

I'm biased and love my hypo jungles, but there are a lot of really cool morphs out there. I would try to pick a morph that would go well with your pastel female so in the future your could mix it up and pair her with the new male too if you decide to get another male.