Hi nycguy. I am looking for kitchen countertops. I came across a company online called Philadelphia Main Line Kitchen and Design. They only sell to people in that surrounding area. However you can email them or call them on Fridays between 2-4pm and ask for advice. They can give you reputable dealers in your area. Their online blog is amazing.
I can't use them because I am in Michigan, but I learned a lot just reading their blog. They do have on their website extensive research that they did only for reputable dealers, all across the US. You may not be looking for kitchen countertops, but I am sure they may be able to help you find something that is good for your project.
I would think though that granite as long as it is sealed on a regular basis, stainless steel and concrete would withstand the elements. But I am not an expert on this. I just look at outdoor kitchens and see what they have used.
