Posted some pics of a few 2x12's I built. I just went in between the dimensions of a Mills Acoustic 2x12 and a Mesa Recto 2x12 with a Rivera inspired style grill. I knew I wanted a completely sealed front loaded cab and I used the breathable partition kinda/sorta like mills use in theirs. I covered them in 1000 denier nylon, Paracord 550 for piping, and nylon webbing for the grill. I'm happy with the way they turned out. It's been fulfilling. My advice is to play some cabs in a music store and find the one you like, measure or look up the dimensions and go from there. Use 3/4 inch void free birch plywood.
The digital camo is mine and I made 2 more for a buddy in woodland camo. Mine has WGS veteran 30's and his Celestion Vintage 30's. http://www.bandmix.com/media/431/431080/659633-l.jpg
http://www.bandmix.com/media/431/431080/659634-l.jpg
http://www.bandmix.com/media/431/431080/659635-l.jpg
http://www.bandmix.com/media/431/431080/659636-l.jpg
hope the pics posted right