You say the zipper broke. Do you mean the slider? Are the teeth still
in good shape? Replacing sliders is easy. I'd suggest the book, "the
essential outdoor gear manual" by Annie Getchel -
http://www.amazon.com/Essential-Outdoor-Gear-Manual-Equipment/dp/0071357122
Also, handsewing really isn't that difficult - the seams on canvas
items are usually pretty straightforward. You might pick up a few tips
on handsewing from the internet. It is easy to undo mistakes and have
a pro take on the repair if necessary. The benefit of learning to
repair your own kit is that you'll be able to do it on tour for
yourself or someone else if it happens again.
As for professional assistance, you might also try going to a
shoemaker/shoe repair shop or a luggage repair shop.
Dave