I ride with a friend who is a big guy.  He is about 6'5" 265lbs.  While being a large person, he is a phenomenal rider.  In addition to logging a bunch of miles (over 140 miles/week), he encourages others to ride and is generally a really good person.

The problem is he keeps breaking spokes on his wheels.  It seems like he breaks one spoke a month or every other month.  Does anyone have a suggestion on what type of wheel should be used by an avid, but large cyclist?  I've already offered to give him money toward lead wheels so I can keep up with him.