If metal is your thing then I've seen the perfect combination for you. All steel for legs supporting frame and top surface then apply a layer of battleship linoleum on the top. I had one like this when I started out at an electronics shop. It was old when I got there but other than the paint chips on the metal part the bench and lino top looked great despite having had equipment dragged over it for years.
To avoid having to make 27 holes in various patterns for the different reloading machines install the machines on adapter plates that are made up to fit the bench holes and then the machines are mounted to the adapter plate. That way you can swap them out easily as needed or just move them when you want the whole bench for some other use of the moment.
Another hint that I learned from my own bench building over the years. Make one leg a little short and install an inset nut, or a welded on nut in your case, then use a big bolt with a foot welded to the head as an adjuster. Even if your bench is truly flat and even floors seldom are polite enough to follow suit. The adjuster makes it easy for getting rid of that last bit of rocking. This has worked so well for me that I use it on all my stands, benches or working tables. Now I'm happy to just get rid of any rocking. I don't worry about it being dead nutz level. But if that's a concern make one leg full length and put adjusters on the other three.
