Hi Kep --Yes, welcome back!!
I'm sorry to hear about the loss of Mrs. Kep and her adventures with you on your excellent trips. You made her an integral part of the Hobie community as well. Please accept our condolences on her passing.
The Revo 13 is a great all around choice and I think you will be very happy with it. Unfortunately I have no experience with the Sidekick. They seem to be quite versatile for mounting location and I think right behind you with the ability to get to them easily for on the spot height adjustment while staying clear of the scupper openings (in case of long cart legs, etc). There was some small controversy about using well nut mounts several years ago but it didn't seem to be much of a problem. Of course, if you can reach the mounting location from inside, I would favor through hull fittings with washer and locknut. Perhaps others here with more experience will have some thoughts to share.
The Star sail looks pretty slick -- at almost twice the Hobie size I think the Sidekicks will be an excellent choice since you can get some good wind up there. The video mentioned "lee skegs" also to aid in tracking and better rudder control. If you get a chance to make a pair, I'd like to hear your opinion on them and maybe a "How-to" if you like them.
In any event, It's great to know you're back -- we missed you!