In the same vein, I have a Psimet kinlin rear wheel laced with a PT and use a wheelbuilders.com wheel cover for ITTs.
He also has some 50mm deep carbon wheels (clincher or tubular) for something a bit more aero when you don't have the cover on.
BTW - where are you finding 20-30km TTs around DC?
__________________
“Courage is going from failure to failure without losing enthusiasm." (Churchill)
"I am a courageous cyclist." (SpongeDad)