If you are looking to make an American style brown (with American, citrusy hops) I would use a clean, well attenuating American ale yeast (WLP001, Wyeast 1056, US-05).
If you are looking to make an English style brown then I would use an Enlgish yeast. If you want low attenuation (more residual sweetness) go with something like WLP002. If you want it less sweet go with something like WLP005. Nottingham might be a good choice if you are looking for a dry yeast.
When you bottle, you should indicate on the bottles which batch each bottle came from. That way you can semi-scientifically learn the difference between the 2 strains, and then you can post back here and share your impressions!