Try to stick to bigger B/T cities that have a community that is concentrated in one area not so spread out.
Miami Beach which has a frum area but I would not recomend it to B/T or not B/T. Same with North Miami Beach because of shiduchim. However Boca Rattan has a very active B/T community and is a safe place to live even though jobs are hard to find.
Monsey is a great choice since it has a B/T yeshiva- Ohr Samaeach and is close to NYC for work. Same with Passaic NJ.
It also depends where you feel you can fit into. Teaneack NJ, and the upper West Side of Mahattan are good for the Modern Othodox crowd
The Pico Robertson area of LA has a nice B/T community but you are limited to shaduchim on the west coast.