Yeah, you should be able to find both species in your area. Warmouth are usually in weedy areas with slow or still water; rock bass are usually in mid-sized rocky creeks with moderate flow. You can try netting or using unbaited minnow traps. If you use hook and line, use a barbless hook for minimum damage to the fish. As always, check state DNR regulations before taking fish home.
You can go down to the Rappahannock to catch the rock bass. The Upper Potomac also has them. Warmouth can be found in the Fredericksburg area and south of there. They aren't too common up this way.
Hit up the Potomac for Rock Bass, they especially like the rocky areas north of Great Falls, shallower and faster moving, Harpers Ferry is a good spot too and so are spots on Goose Creek where you can gain access. There are numerous places in the NOVA area that you can get Rock Bass from, mainly a creek/stream/river that has moderate flow and has good cover, they like rocks (hence the name). Those suburban neighborhood man-made ponds that dot the NOVA landscape probably won't net you what you are looking for but you can find some lunkers. On any given day on the Shenandoah you can pull in smallmouth, rock bass, largemouth, rainbow trout, brown trout, brooke trout, muskie, pike, etc. I know of a few spots where you can get all of those species in a day, and thats pretty impressive but I cannot publish my secret fishing spots.