I've been looking at UMPCs - these are laptops & tablets that have screens smaller than 10". They usually are in the 4" to 8" screen size, and can have extra large batteries that last up to 12 hours. Weight is usually under 2 lbs, before the extra large battery.
Check out
www.umpcPortal.com
For tablets, Fujitsu is the best, but they cost quite a bit. I picked up a Stylistic 3400 used on eBay for $300 loaded, but battery life is limited, even with extra batteries and external dual chargers. You don't need a lot of processor to read pages.
I've seen the Fujitsu St5111 listed as a good option, but we're talking $2500.
Andy