I just want to say thank you to everyone that participated in this thread and all of the helpful suggestions I got from it.
I went with a 16:9 aspect ratio on mine after finding an absolutely perfect piece of do-able at home depot. I also bought a 1/4" thick piece of plywood. The other items I purchased were 8ft of black velvet from hancock fabrics, two tubes of 8x strength loctite, a can of spray adhesive , two pieces of 2 1/2" mdf to make the french cleat, one piece of 1 1/2" to use as a spacer , and finally 4 pieces of 3 1/2" mdf to make the frame.
1x piece 4x8' do-able board (SKU # 174278) ($23.15)
1x piece 15/32 x 4 x 8 (SKU # 915378) ($17.95)
1x 11/16"x1.5"x8' (SKU # 226619) ($3.66 ea)
2x 11/16"x2.5"x8' (SKU # 226510) ($5.32 ea)
4x 11/16"x3.5"x8' (SKU # 242738) ($7.46 ea) You could also do 2x 8' and 1x 10' which would save you about $5. The 10' is $9.57 (SKU # 242741)
2x Loctite Premium Adhesive (SKU # 908537) ($7.85 ea)
1x 3M Spray Adhesive (SKU # 364533) ($9.99)
8' black velvet from hancock fabricks ($23)
Total = $133.93 + tax
1. To start, I used one tube of the loctite to fasten the plywood to the back of the do-able to increase stability and give a deeper surface to fasten the french cleat to.
2. I then cut a 1/8" dato into each of the pieces of trim. At the ends I took half of the thickness off the back of the top and bottom and half off the front of the sides.
3. I used the can of spray adhesive to spray the velvet and the trim and wrapped the velvet about 1" around the back. Using a razor blade I then cut the velvet inside the dado to allow the do-able board to trap it into the recess.
4. At the corners, I used some more of the loctite adhesive to hold the frame together and then folded the velvet over.
I used more loctite adhesive and 1" screws to fasten the french cleat and spacer onto the back of the screen.
5. I stapled the velvet into place on the back and then ran black duct tape over it to keep it from fraying.
(puggle included for proportions)
It ended up being a little more time consuming than I expected with ~16 hours from start to completion over a two day span.
I'm using a BenQ W1070 that I purchased for $677. So all in all I have about $825 into the entire system and I can't believe how great it is working out. I switched from a 52" LCD so it's pretty much 4x the size. I have two windows in the room that it is set up in but I have a piece of foam board that I cut out and put between the blinds and the window on the larger of the two. This keeps the ambient light from being overwhelming.