Here we go boys...my first post.
Like the OP, I've been tossing around the idea of making a false bottom and found this idea.
Seems simple enough. No need to worry about drilling all sorts of holes, and a pizza pan wont leave much dead space at the bottom either. Ultimately, a false bottom is just there to help filter out the majority of particulates when sparging. Why overcomplicate it? Anybody have any reason to not go this route?
the holes may be too large, not enough of them and the metal might be too thin to support the weight of the grist but for $10 it's worth a try:) report back with your results.
As for the OP, if recommend the 10 gallon tun for larger grain bills and more flexibility with the water ratios being used.
Batch sparging is great, I average 80% efficiency and use a false bottom set below the plumbing with a dip tube. Dead space is about a cup of wort.
No offense to Denny's screen setup, I just never got good runnings no matter how I set it up in a round cooler or the materials used but YMMV:)