Sony VW40/VW60 on 18' throw distance

Since you are using a 2.35 aspect ratio sceen (Dalite High Power?) the best setup would be the VW60 and the use of an add-on anamorphic lens. The VW60 include a video processor that can do the required vertical stretch to fill height of the screen (the VW40 cannot without the use of an external video processor) when using the anamorphic lens (to do the horizonal stretch to fill the screen width). This setup should be bright enough given your high gain screen. The lower cost alternative is to simply use the zoom and lens shift settings to expand both vertical and horizontal size when viewing 2.35 'scope' movies then zoom back for 16 x 9 material. This wouldn't produce as bright an image as the first alternative but can work if you keep the area above and below screen covered in flat black material.

As for distance the ProjectorCentral calculator shows for the VW60 and a 127" wide screen (and the projector zoomed out to fill the full screen width) the projection distance can be from 14' 11" to 26' 7". Then to zoom in for a smaller 16 x 9 image and for your screen's 54" height the projection distance range is 11' 3" to 19' 4". Thus if you want to use it in one mode for watching regular HDTV 16 x 9 material (aspect ratio 1.78) and in the other mode for watching 2.35 scope movies then the only available range for projection distance is from 14' 11" to 19' 4" and your 18' number falls within this range so it should work. If you want to go with the add-on anamorphic lens then the projection distance range listed above for a 16 x 9 image (i.e., 11' 3" to 19' 4") would apply. Remember the projection distance is from the front of the projector's lens to the middle of the screen.

Check out the forum thread on 2.35 constant height FAQ

Are you using an anamorphic lens for CIH?

That calculator is going to be based on a 16:9 screen, so unless you're using the zoom method to do CIH instead of a lens, you'd want to use 96" as the width.

You may have to use high mode for the bulb to get enough lumens. I have my VW40 15.5' from a 48" high 2.35:1 screen and am able to use low mode, but IIRC I measured only around 9 ftL, which some may consider too dim. It looks fine to me, but as the bulb ages I'll probably end up switching to high mode at some point.