Idaho Underground was available at Elephants Perch but they sold out. I wast there yesterday and they said there were going to get some more. David Bingham, the author, is on Mountain project somewhere, so maybe you could talk to him.
Yes, the book is at the Perch, but truthfully does not have a lot of bouldering info for the SV area. The best area - The Channel - is flooded right now, but there is some decent bouldering up Trail creek rd, uphill from the lefthand bend in the road before the roped climbing area.
Prarie Cr. (15 mi. n. of Ketchum) has a fun boulder in the pines 2 miles up from the highway.
There is some ok bouldering at Redfish (ask in the lodge) or up Redfish Canyon at valley of the Giants.