You guys are thinking about this all wrong.
If you consider that the books, caliper, powder, notebook, primers, bullets, etc (all the reloading gear) can easily be supported by the most rickty card table, then it's only the press that needs support. If that's the case, then the only reason to build a huge bench strong enough for King Kong is to blow lots of money.
The stongest press support needn't be any more complex than a single 4x4 used as a leg directly under the press, capped by a 18" x 12" bench "top" anchored to the studs inside the wall behind. The leg prevents any deflection, the wall prevents any side-to-side. Simple and effective. And you can get your legs underneath it.