I have the first one and it works well. I really like having the ability to quickly pull the pin to pull the lid off for pre-cook prep and cleaning. Then it can be re-attached easily by putting the lid in place and popping the pin in. Having the hinge makes using the WSM a pleasure for me - along with my other mods. As far as the cover, mine would not fit after adding the hinge - but I also added handles and a lavalock door which was the main reason for needing a larger cover. Yours might fit ok if the hinge mod is all you're adding.
Best of luck!