looking for product

We are a full time emergency vehicle upfitter located in eastern PA. Recently we have had several jobs requiring the installation of in-dash GPS systems and to date we have been farming this work out but due to time constraints we may soon need to bring this work in-house. Are there any wholesale distributors in our area or shops who may be willing to wholesale to us? We ARE NOT looking to do installs on a daily basis but rather add it as a feature of what we can provide as a total package for our customers. Any help would be appreciated.

Really? Nobody? OK, well then will be shopping the interweb but would have rather done business with someone we could lean on for support on product.