The color Kindles and Nooks are all fine, but my boss got the Nook color and has now picked up a regular Nook with the E-ink technology because the color backlit screens do not show up well outside.
I wouldn't buy a quilt book for a Kindle or Nook anyway since I wouldn't want to have to look at it on a screen while sitting at my sewing machine and what if there are templates, you can't print from a Kindle or Nook.
I would suggest getting the 3G version no matter what, because I absolutely hate having to find a Wifi signal if I'm not home and want to access online content. I'll sacrifice color for 3G any day.
I will probably upgrade to the newer version of Kindle 3G and E-ink technology when they come out.