I don't think there is anything special about a reloading bench; any workbench that is 24-30 inches deep and 5-6 feet long should do. I built mine out of 2x6s and 4x4s about 20 years ago and it works just fine. I probably spend $10 for lumber and fasteners back then; today it would be three times as much, but still a bargain.
A couple of small points:
When I built the bench, I had an overhang of about 2-1/2 inches at the front. Since most presses tend to want to lever the top (particularly if it is a 2x6 board) up over the front rail, I filled in the overhang in the region of the press with a ripped length of dimensional lumber -- essentially a large glue block -- hogged out where necessary to pass the nut on the bottom of the Rockchucker handle.
Second, I'd recommend against either lagging or ram-setting the table to the wall. True, you need to keep it from trying to tip toward you when case forming, but it is sufficient to lag or shoot a 2x4 ledger into the wall under which the rear of the bench top will just fit. This way you can move the bench, if needed, without a lot of work. (What I did was to shoot two pieces of 2x4 vertically; onto them is mounted a piece of 3/4 plywood which serves as a mount for shelving and assorted tools. The butt ends of the risers act to keep the table from tipping.)
For tools that only need to be secured to the bench on occasion -- trimmers, auto primers, etc. -- I just drilled a couple of 5/16 holes to line up with the base of the device. These were then recessed with a Forstner bit the thickness of a 1/4 nut and washer. Now two bolts are inserted, head end down; mounting and dismounting the device takes only a couple of seconds, and they aren't in the way when you want to use the bench for other things.
