I have built 7 or 8 benches very similar to what you described for prairie dog hunting for our group. The first one I built is the sturdiest as it uses 2" (or 1.5" cant remember) well pipe for legs. After I cut out the 2 layers plywood for the top I cut 3 pieces of 6" 2x6's for the leg bases, rip them at a 45 degree angle and it gives you a perfect angle to mount the leg brackets too. The other tables I have just used folding table legs that you can get at home depot for $20. Munch handier but a touch less sturdy. Ill try and get some pics up for you.