I'm just getting started on a long-term project involving northern Delaware. Most of my distances will use great circle distances from the lat/lon, but for a few applications I'll wind up using standard distance functions (e.g.
gDistance from rgeos). I'd like to pick an equidistant projection centered in this area (say, on Lat +39.7033053 Lon -075.6867863). The distances involved are small (about 15 mile radius), so it's not critical, but it would be nice to not be using a grossly inappropriate projection.
Can I take something like the USA Contiguous Equidistant Conic and re-center it on that point, or is there a better projection for small-area analysis? If the former, how do I do it and get a proj4string at the end?