Well, actually getting the sled to track well can be solved with some of the ideas on skipulk.com. I'm having real issues with building a suitable enclosure. I used irrigation tubing to build a frame for the raincover for a BOB stroller to sit on top of. Unfortunatly its not long enough and wind/snow can get in really easily. I need a way to seal the little one off better from the elements.
Also, I'm using a crazy creek type chair. That dosn't work very well. Any other ideas? I am thinking of a sea kayaking type backrest and just closed cell foam on the floor of the sled.