Mark,
I-64 goes through the Hampton Roads Bridge TUNNEL, so THAT one is out. I-664 goes through the Monitor-Merrimack Bridge TUNNEL - ditto.
Rt. 17 is the ONLY one that doesn't have a tunnel - and that one will bring you out pretty close to Hampton! It's also the SHORTEST way to get across the James, given the "CNG" situation.
Are you SURE the M-M Bridge Tunnel won't let you across there? They DO have an "inspection station" on the Chesapeake side? I don't know ANYTHING about what "gases" can be taken across, and how they are treated by the authorities?
I imagine weekday "morning and afternoon" rush hour could be pretty nasty on the Rt. 17 bridge. Saturday/Sunday is probably not that bad. I usually use the I-664 to get from here to OBX.
REELWORK has FREE beer, steamed crabs, and hushpuppies EVERY weekend at his home - for the "traveling public"!

He'll probably chime in here to get you "around" in the Hampton area!
Have a nice trip - VERY interesting area!
Regards,