I know a couple good upholstery/convertible top guys and they can definitely do the job. That's the way I'll go when mine eventually cracks.
But, try to source the material through them rather than pay $80 for what is essentially a sheet of plastic with some rudementary tools (which neither you or they will use).
There is lots of good sheet vinyl out there today, and if your guys are good, they'll know where to find it. Take this stuff for instance:
http://www.yourautotrim.com/40gaug27clea.html it meets the necessary specs and would cost only about $30 for the raw material, giving you an extra $50 to give the upholstery guys. This is the vinyl used by the top manufacturer Bestops.
Threaded Mode
