Those pads will be great for car camping or a level easy backpacking trail. You really need to consider weight more carefully for backpacking up a steep trail like Whitney. You really shouldn't need two pads either unless you're camping on snow and need the extra insulation. I have every pad mentioned in this thread and a few others as well. Like Steve, my favorite is the NeoAir, but I like the regular length. You might look on Craigs list or Ebay or a closeout sale on a basic 1 inch thick Thermarest (or similar brand) self inflating pad, about 1 to 1.5 lbs.
Here's one I found on sale in 20 seconds online for $60 weighing 1.25 lbs. I just noticed the NeoAir short is onsale at campmor for $80, great deal and super light if you're okay with the shorter length.
http://www.campmor.com/outdoor/gear/Product___40217
