Either way you get a Panda.

Black Pastels and Cinnamons are similar to Lessers and Butters, either way you get the same results. They're different in that the results have more range to them.

Personally I'd kill for an Ian G Black Pastel, because the end result of them is usually a nice solid black super. It's all up to your personal taste, and if you want a brown one I'd suggest messing with Cinnamons. The best option would be to get a couple more brownish supers, then breed them, select the browns you want for a couple generations, and hopefully produce a reliable line of brown snakes...

But thas assuming you have the funds and an infinite life span, these aren't pea plants, you know.