Well I ended up going 40" high. Here it is ... and it's rock solid. Just have to build some shelves for the bottom and top.
The wood and the screws only came to 60 someodd bucks too.
X2. Bart212's set up is very nice. For my needs though, it would be to small. If you aren't pressed for space, build it as big as you can. Mine is 8 feet long and 32in deep. That leaves room for those handy little storage units at the back and some shelves, around 8in deep.
If you're going to load a lot and stand, you don't want to be bending over.
I set my powder measure on an iron pedestal, that I made up from a piece of scrap 2in x 6 in flat bar and bolted on a 6in x 6in x1in steel base. I want to be able to move it out of the way, not bolted permanently in place.
My beam scale is sitting on a level shelf that is slightly lower than eye level but not so high that it's uncomfortable to add powder with the trickler. Really cuts down the clutter on the bench. I have four presses mounted on my bench and it doesn't take a lot to clutter things up. The digital scale, sits right on top of the bench. It doesn't need to be higher.
As mentioned before, set up lights, lots of them. Recently, I helped a friend set up a loading bench and we installed a 4 tube, fluorescent fixture with 48in tubes. We hung it from chains to be closer to the work. He didn't want to cut holes in his sheet rock to install wiring, so we just ran an extension cord to a wall plug.
His space was limited to 4 feet by 6 feet, under the stairwell.
The wall plug is very important. It should be above the top of the bench, rather than underneath. It was relatively easy to install it by taking the power from an existing plug mounted just below it. If you're going to do this, do it before installing the bench.
build your bench with an overhanging top. That way you have room for your feet or knees if you use a tall stool. Also, put a rubber mat on the floor. As we get older, that darn concrete gets harder on the feet and knees, causing your legs to tire and your knees to ache.
Don't waste the space under the bench. Install heavy shelves that are big enough to accomadate those plastic totes that are so cheap. They can be used for storing brass, or whatever and because most have lids, they keep the critters and dust out.
Make the top as rigid as possible. A top that flexes while you're operating the press is a pain in the butt and can cause spills. Mine is 3 sheets of 3/4in fir plywood, glued and screwed together, with an arborite top.
It only took me 35 years to finally put together my ideal set up. I made several mistakes along the way. Mostly because of financial constraints. You have to do what you have to do.