Flippy, all I can say is I am glad I don't live in eastern oregon. I would never work and my ammo bill would be never ending
Heres a link to those brackets on eBay.
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=7207...TRK%3AMEWA%3AIT&rd=1
The nice part of using brackets like this is, if your not happy with the design, just remove the brackets and start over. I have a note pad with several designs and several proto types that I have tried.
The design pictured is one of the better ones as if you want to shoot standing up, just purchase longer legs. It is also nice, in that when moving to another site, I just flip it over and slide it in the PU for the move.
I will say that the BP Pivot is the cats ass when it comes to benches, just not my cup of tea for the sage rat hunting as I seem to move quite often.
Now, for portability, look at that little setup my buddy used in the first picture. It is not a bench but a pivot stool type of thing with a arm that comes up between your legs with a Y to rest your gun in. It might weigh in at about 7-8 lbs and plenty steady for the 2-300 yard shots. I think he got that one from Cabelas.
I am lucky as I have a shooting buddy that has a machine shop and can fab and machine pretty much whatever I can dream up but with his imput at times.

We discussed this in a similar topic earlier:
Portable shooting bench

Maybe it can give you some ideas?