There are many that will do well in Zone 7, both running and clumping. It all depends on what size and characteristics you're looking for. Below is a link to a well-regarded bamboo nursery in your state. I suggest you call them and discuss your needs.

Here is a link that might be useful: MidAtlantic Bamboo

Wow, what a nice site, they are near me too, so I won't have to wait for UPS, thanks so much for the info, vickie

If you want clumpers, I've have nice experience with Fargesia ruffa, and Borinda angustissma. I had other Fargesia but they seemed to die out when I had them planted in a sunnier, warmer (and winder) site. I have these two now in a more semi-shaded position. Many clumpers (largely species of Fargesia, should do fine in your zone 7, if you position them appropriately in your yard). (I am experimenting this year with Bambusa multiplex, another clumper but less winter hardy.) I find the clumpers to be somewhat more temperamental with respect to sun, watering, exposure, etc. so to some extent experimenting may be helpful until you find a site they like (transplant fairly easily). Among the runners, there are MANY varieties that will thrive for you. JUST SERIOUSLY CONSIDER HOW YOU WILL CONTAIN THEIR GROWTH. I like Phyllostachys nigra (Black bamboo). This species is NOT AS aggressive as others in the genus. I also like Phyllostachys viridis "Robert Young" (bright yellow culms). (The commonly available Golden Bamboo, P. aureus, seems to me to be one of the more aggressive Phyllostachys species.) You could even start a giant Moso bamboo grove (P. pubescens)--just am starting with this species. Most runners thrive in eastern zone 7's. (PS. Sorry I can't help on purchasing as I purchased my running varieties years ago, and once you have them you never need to buy more.)