Thanks to your help, I probably won't even mess with the wall paper.  There seems to be other easier and cheaper options. 

Thanks for your help!

To add to what Gaafa has offered, do the daubing technique using a miriad of odd items for texturing.  We've used feather dusters, bunched up garbage bags, torn sea sponges, gause, dry texture brushes, etc.  Use three colors; a base color followed by texturing in first a contrasting (to the base) color and then a complimentary (to the base) color.  Take care not to over-load the texturing with paint.  Pat the "texture material" on something to dry it out a bit (newspaper, scrap wood, paper towels) before applying it to your flats.  The texturing should be in a totally random pattern and not so strong it becomes distracting.  It should give the walls a look of "vibrancy," making them much more interesting and appealing, but subtle enough to prevent distraction.

If using a stencil, where you WANT a repeated regular pattern, make two stencils, side-by-side.  Use one as a locating guide and the other to paint the pattern on the flat.  Use the top and bottom edges of your stencil to guide you along one row to the next.  I would recommend doing all stenciling and texturing with the walls up and assembled so there is no obvious sudden break in the pattern from one flat to the next.  Trim around doors and windows after finishing the walls.  Good luck!  Your set will be wonderful.

Should you decide to go with wallpaper on wood flats at any point there are a few helpful things to keep in mind.  Make sure the flats are primed. (New wood can be hard to clean up after).. I use the pre-glued wallpaper, goes on quick and fairly easy.  After the show, we use vinegar, water and a scraper to peel it off. A little extra work there but it keeps the flats ready for whatever is next.