You should keep in mind that manual screens have serious isses with getting waves in the material over time. Within about a year or so these waves will be visible all the time, and will be distracting from the viewing image during scenes with panning in them.
Knowing that, I would recommend a fixed frame DIY option, like a blackout cloth screen that you hang from the ceiling and can lift out of the way when not necessary - on hinges will allow it to swing forward entirely when not needed.
If you are determined to use a manual screen, I would specifically avoid Elite after seeing one and immediately seeing a rainbow 'shimmering' effect from an AE700 projecting onto it. After seeing the Elite screen material, I would be hard pressed to recommend it to others. Just not a great product IMO.
As for the Optoma Greywolf, which is very popular, I am not sure how great it really is, or even how much you need the higher gain it offers in your pretty much ideal setup. Small screen, dark room... it screams for a fixed frame screen for maximum quality.