Memory serves me right, kindlegen can use .doc files as input.
Mobipocket creator certainly do.
http://www.mobipocket.com/en/downloa...ilscreator.asp.
What kind of .doc are they ? just text ? Or is there table and other "complicated" stuff ? If that's the fist, mobi will be much better than pdf.
If it's some pdf you read, the sony might be better choice than the kindle. (I can't speak from experience having neither kindle and sony, but I've heard that pdf support was better on the sony).