seth:
my advice is not based on whether you can get in somewhere, but why settle for (anywhere) when you have a chance for a top program? While fine institutions, the McNair list of ~180 excludes nearly all of the best of the best. By my quick read, Berkeley is the only top 10 uni in Enviro Sci that is a member of McNair. (Altho I might have missed one.)
And IMO, the higher the better for a PhD. Going to a low-ranked school for your PhD will close a LOT of doors. Moreover, the tippy top privates are rolling in dough, which they can spread around to grad students.