| Absolutely. I've actually gotten heavy duty canvas needles at Walmart or Kmart, but only because fabric stores have become more rare- they are your best bet and will generally have higher quality and a better selection.
You should also be able to find heavy project thread, designed for canvas or other heavy materials. IME mending seam rips in my old tent camper in the 70's, I learned that using a decent pair of long nose pliers was often most effective at moving the needle through multiple layers of heavy material, rather than using thimbles, to avoid injuring fingers.
You are wise to keep on top of bag maintenance, you can get a lot of years out of them. Regardless of quality, they all can give at seams or tear due to heavy use or accidental stress. | 
