Wherever you get this done,
be it a awning shop, upholstery shop, or even a sail loft, make sure the thread used is UV stabilized -- or you'll be making a return trip sooner than you might like. FWIW, you can do a lot of your own stitching on most home sewing machines as long as you use a heavy duty needle, set the tension correctly, and don't try to sew too many layers at once. I also use a hand-stictcher that you can buy at most chandleries for around $15 and it is a very handy device.