+1

"Soft tissue" issues are a big problem. I need to visit my LBS and get some help finding the right saddle and get my bike fitted properly, which I foolishly didn't take time for when I bought it. Buying a nice Brooks sprung saddle didn't do the trick. Maybe take him to a good LBS and buy a reasonable men's bike and have him pay to get it properly fitted? He'll wander in again to buy a really nice bike after he's hooked.

Also, fixing his diet will be far more effective at shedding weight than exercise alone. Removing sugar and HFCS (and artificials, ESPECIALLY Nutrisweet) will do wonders. You need to do this too of course. Once I lost most of the fat I was lugging around, exercise became a lot more fun and took care of the rest.