Be sure to check out RVupgrades. I guess it's okay to say this but if not, I'm sure a moderator will delete this post but RVupgrades is not only an iRV2 sponsor but is owned by the founder of the iRV2 forum. Excellent customer service as you will see from the many testimonials on this forum.
If they don't stock it or can't order it, I'm sure they can refer you to a reputable vendor -- 866-332-7881
I was surprised at how fast the last item I ordered was shipped. They seem to have some of the lowest prices around too.