From IAH you're correct you have 777-300ER (77W), forget if they're using the version with or without Comfort Class at the moment, the Business Cabin is much smaller on the CC version which I'd personally prefer but no big deal either way. Your 737 flight is an uncertainty, they have 737-500, -700, -800, and -900 in the fleet and generally swap similar aircraft at will so even whats on your itinerary may change. The -700 and -900 have the new business class, all the others have the old Euro style. For your KWI flight, all the Airbus A319/320/321 have Euro style.