Any Park Stream is good,some are better.
I think you will enjoy your trip no matter which Stream you choose to fish.
If you contact the Park,they can send you a list of Streams open to harvest.
I began using an 8'6" in the beginning,(a 6 weight mind you.
),then after catching enough overgrowth/canopy/bushes on backcast's,
I got a 7', 3 weight G.Loomis Streamdance Metolious.
Loved the rod,its the only +$300 dollar one I own,
but for one Xmas my Father in law,who is a big bass fisher bought me a 6'9" Bass Pro Shop 4 weight.
I had seen the Light.
I immediately got a 6'3" Bass Pro 3 weight and never looked back.
Great Rod with a high Modulus at a great price.
Then I finally ended up getting a Lamiglass 6'6" Appalachian Trail 3 weight when our local fly shop went under.
There are only a few places here where you will have more than 30 feet of Line out.
By the time you guys arrive it should be okay for "wetwading".
Any Flies should do just fine,I always run a "Dry/Nymph" combo,to cover the water column.Guess I should run an Emerger between the Dry and Dropper?.
Here's a Hatch Chart if you want;
virginia fly fishing: fly fishing virginia and fly fishing guides. Fishing in Virginia for Virginia trout and smallmouth bass in the Shenandoah Valley and the Shenandoah National Park
Good luck,I know you will enjoy,Stix.