I would try Go Westy (www.gowesty.com) for your canvas.  However the
replacement of the canvas is not for the light of heart.  It is at least a
8-10 hour job.  And it can be very frustrating.  It helps to be artistic and
have some mechanical abilities.  I had my father install one here at the shop
and while he did an excellent job (fit like a glove) it took him 10 hours.
Now that he has done one he could probably do another one in 8 hours or maybe
even less, however since you are probably only ever going to do one, just
plan on the time investment being high.

Thanks,
Ken Wilford
Van-Again
John 3:16
http://www.vanagain.com
Office: (856)-765-1583
Fax: (856)-327-2242