So, another obsession of mine is never having two teams in the same city limits. To that end, the Angels in my game almost always wind up moving out to San Bernardino and becoming, once again, the California Angels, while the Mets frequently find themselves moved to New Jersey (I never have a good solution for the White Sox... maybe move 'em across the border to Gary and make the the Indiana White Sox?). With the skyline of Newark behind, may I present the primary logo of the New Jersey Mets:
There actually seems to be a company that sells hats with a cursive NJ embroidered on them in the colors of various NY/NJ metro teams, including the Mets, so I created a cap that is essentially a shameless rip-off of that below.
For a jersey, I typically just use current Mets gear.