Buddy(s) wanted for Ironman!

I have done a handful of Tri's and really enjoyed them, however with age (54) my left knee doesn't like the continued impact of the run but I don't want to give up Tri.  Is there a site or are there people here that want to 'buddy up'  I can swim! I can ride a bike!, I just don't want to limp for the rest of my life because of excessive running!  C'mon guys and or girls any other keen 'groupers'??