You must be on Ecomodder... Actually, I think I might remember seeing your other T there a year or so ago? I owe my 17MPG to 21.5MPG increase to them.
Unfortunately my T sees too much horse pasture to do anything that might break off road. I had been thinking about building a coroplast belly pan... but all of the other stuff that needed attention side tracked me.
Have you thought about side skirts or that crazy inflatable boat tail? How bout some wheel skirts? I like the roller design for front wheel skirts.. might have to try that. I always thought a set of aluminum reinforced, coroplast walled side skirts that could hinge up out of the way when you need the clearance would be interesting. Use a set of door openers to keep 'em down, and just use a latch o cable pull to pull them up. Too bad that guy that was making slope-back caps never got around to doing one for the Tundra or T100. Then you'd really be sip'n.
When I have to start commuting again I think I might pick up an old civic or CRX and aeromod the hell out of it. Unless I start getting some other offers it might be an hour commute at highway speeds. A 60MPG aeromodder might pay for itself quick as compared, even to a well configured T.
I'll stop mumbling now. The valance looks good- definitely go for both aux driving lights and fog lights if you can. I had such a setup on my jeep and always kept the fog lights pointed just a bit out... Great for spotting deer (or the deadlier moose) in the Maine woods.
Cheers,
Rob