There's also the thought (although it adds some cost) of supplementing the ipad with a keyboard; ilounge reviews one
here, but there are several others.
The Apple store has refurbished original ipads for $150 off the original price - $349 for the 16GB version. I got mine from Best Buy for around that, it was an open box. That was last Friday; presumably someone had returned it in favor of an ipad2.
I wouldn't recommend upgrading your laptop to windows 7, unless it was a very high end model when you purchased it. Even then you probably won't get your money's worth out of the upgrade.