that is a start of course, this way you wont have too much money involved if it doesn't work. like Mike said find your self an old projector and uses the lens from it. it might be a bit more (wide) viewing angle . are you looking into like a spot or wide angle. now I'm not sure and don't remember anymore, I think you can change the viewing angle with an iris or a proper sized hole in a blocking plate in between the image and lens(image, plate, lens) its been 35 plus years since I played with optics in science class LOL. let us know how its working out and pictures would help to see you're set up.
Alan.