Check
www.kawasaki.com for Vulcan 750 accessories. They list several models of saddlebags that fit the stock Kawasaki brackets, but they are not cheap. They only have 2 models under $400. However, you might be able to do a lot better than that at an online dealer, such as Michael Andretti or Ron Ayers. I got mine at a considerable discount under list price from Michael Andretti Powersports back in '02, with no shipping and no tax.
There are also much cheaper ways of doing bolt on saddlebags. On my '93, I had the same mounting brackets, but rather that the expensive real leather saddlebags, I had a pair of Willie&Max Compact Slants throwover bags. I took a seam ripper, and painstakingly removed the sewn on yoke, then made holes in the bags that lined up with the brackets. I used a 1 1/2"x1/8" piece of steel with holes drilled in it on the inside as a stiffener, and fender washers between the bags and the mounting points on the brackets on the outside. It worked fine for 80,000 miles. Jerry.