I've had to expand my reloading bench a couple times . I now have a "U" shaped bench . two of these have kitchen counter top , which I really like . the newest piece I put 3/4" plywood with a layer of that cheap white board that is used in showers and other places . it's kind of like a porcelain coating on it . this stuff is not durable at all , I wish I would have bought another piece of counter top for the work top . this stuff is great for a nice smooth cover on your shelf though . I agree with the other guys , you want the bench built solid , no rocking , or wiggling . my original bench I used round pipe legs . I welded a plate on top and bottom . I mounted my press over one of these legs , and bolted through the metal plate . the metal plates on the floor are tapconed to the cement basement floor . I tapconed a 2x4 to the basement wall to support the rear of the counter tops . my last addition to the bench I took pictures as I built it . I'll post some of these up , they might give you some ideas .
my suggestions to you are ;
1) build it bigger than you think you'll need .
2) use something durable for the top . I really like the kitchen counter tops ,
3) make it solid .