Concerning ground sheets:
When we expect bugs I use a RayWay bug tent, the old style, with a silnylon floor. Otherwise I use a large Polycryo ground cloth (I got it from Gossamer Gear, but they don't carry the large any more).
The new style bug tent, recommended on his web site, incorporates a zipper in the entrance. I plan to add the zipper to mine.
I've heard that 3 mil plastic works fine, as does Tyvec house wrap, but I have no experience with either. You probably can find silnylon remnants at online fabric places and just cut a piece to size.
I think "Trail Life" is a fantastic book...I have nothing to add to it!