One way that the handles wound not be on the very top of the bag is to flip it around (according to your picture) to where the color block is near the top. That way the handles could be inserted into that seam and it would eliminate the stress on the zipper. Make the outside with the handle attached, the inside lining and sew them together. When you flip the bag, it all will be right for you. Hand stitch the opening together and voila there it is.