I've got a couple of mountain bikes I've fixed up for touring. They work fine except for one thing: I keep breaking axles. My mechanic tells me I need to get better wheels because of the amount of weight I carry, but touring bikes aren't really his forte, so he really wasn't able to recommend anything specific.
I'd appreciate your suggestions. What should I be looking for? How many spokes? Should they be stainless steel? Double butted? How much will I have to pay for something decent? Brands?