Assuming that for now cutting sheet goods is your objective, and the clamping versatility of an MFT style top can wait...
Do you have a track saw? If not then you could first try a scaled up version of Dan Pattison's crosscut jig: search "circular-saw-cross-cut-jig-pt1".
If you have a track saw the simplest way to try out the concept is to buy two tall bench dogs and an appropriate bit. Set them up as shown in Peter Parfitt's Speedy Cutting Station video. Instead of trying to get a row of dog holes across the top at a perfect right angle to the fence dog holes, clamp a wooden fence in place as accurately as possible, and perform the four cut test to calibrate it. Also called the 5 cut test; Peter and others have videos. When it's accurate enough screw the fence down.
From what I've read plywood vs MDF is mostly a personal preference, the main differences probably being cost, weight, and apparently dogs fit a bit more tightly in plywood.
On the other hand the CNC tops mentioned earlier in the thread seem reasonably priced and provide a lot more functionality.
Good luck!
