For flat top stoves, canners should be no more than 2 inches wider than the diameter of the element. Some people have given up on canning on their glass top stoves and use a portable propane cooker outside to can on. My friend made jam on her new cooktop and the sugary jam made permanent pitting on the stovetop.
I have read a few people who sucessfully can on them, though. I think it all depends upon your particular stove. I would oontact the maker of the stove or check your manual to see what it says.
There is an electric water bath canner you can buy, but they are out of stock now, and cost nearly $200. They are Weck brand. I used one in a food safety class. So, there are a few other options for water bath canning.