I'm using a false bottom, in my keg mash tun, from NorCal/Jaybird... I went with the 15" model, with the handle and hinge (so that I could get it in/out of the keg) and hole drilled in it for the dip tube. Works GREAT.
What are you planning on using the false bottom in? Instead of going the cheapest route, why not get the correct one for the job? You don't need to go with the most expensive one, just one that's not going to be replaced later when you're fed up with it. I've done that with enough hardware to be good paying a bit more the first time. That way, it ends up costing me less in the long run (when I get that item anyway)...