I just got this case for carrying my iPad :
It has rigid sides, can hold the iPad (or any reader) in whichever skin/case you may have it in - and has a panel to securely hold cables, accessories, etc.
You can look here:
http://www.levenger.com/PAGETEMPLATE...-3|PageID=7358
and here:
http://www.levenger.com/Pagetemplate...MorePhotos.asp for more photos.
I've bought cases from Levenger before - pricey but very well made.