Timmy - it's getting late in the season to purchase roses or fruit trees. That said, you can order them online, my guess is that nurseries have cleared their stock by now. I know the ones i visit have had their end of clearances and only have winter ready stock. Some have closed for the winter (or have started reducing hours).
The ground is still warm enough that a tree might survive a planting if it is hardy. I'd recommend waiting to spring, but if you can find a clearance deal (either online or still at a nursery), plant it in ground quickly and give it protection. Or depending, you could pot it and then plant in spring.

If you're in Northern VA, Merrifield Garden Center is one of the biggest nurseries around and has tons of roses. For online shopping, HeirloomRoses.com has a huge variety.