Cool story. I really liked the Sentinel addition; I've enjoyed a number of SG-1/Sentinel crossovers and always thought it was a natural. Of course they would be even more useful on a gate team if Jim didn't have trouble adapting, but that makes them going to Atlantis more believable, not less. I'm going to start the new story now that I've caught up - I read Cross Product, but missed this one.
Cross Multiplication