Oh, you may be a bit out of date if you think WW isn't compatible! Check out the new list. http://wiki.gbatemp.net/wiki/Loadiine_compatibility_list
I also mentioned it in my second video as working without needing Smash Bros. If only they can get Bayonetta 1+2 and Super Mario Maker to work then I'll be in paradise. I edited the post you quoted to say that Mario Party 10 also has the 5.3.2 update. If you can rent it, then you'll save some money unless you're planning on returning it or something.
Sorry, but I'm quite new to Ebay, but how do you know if the version is 9.0 or 9.2? i've been looking there but I can't find a way to check the firmwares.
thank you!