Originally Posted by Romelle

I do agree with the open-jaw route.

Starting in London lets you train through the Chunnel. I found this very exciting, although fellow passengers were reading newspapers and nodding off during what they considered a non-event. Running time is only about 2 hours, and you start in St. Pancreas Station, London and end in Paris Gare du Nord. No long trips to/from airport and easier security. People in London and Paris actually can treat the other city as a "day trip".

We aren't being very helpful with your original question on United business class mileage ticket redemption. You might prowl the United specific area on this site, and also the hotel specific and the Chase specific areas.