If you want to go ahead and "reserve" a certain combination, just use the general "comments" tab at the top of the page (right above the video) to tell me what you like or want! Feel free to suggest straps, too, as there is still plenty of opportunity to include some good ideas in the collection.
You can always change your mind up until we send out an official survey after the campaign ends (and we get funded!) to take the actual orders. Sometimes it just feels good to be accounted for ahead of time.
Good luck making up your mind!