One of the best things to use are kitchen counter tops. You can probably find damaged or blemished ones at your local counter shop.
One other thing to keep in mind, the height of the bench is important. If you plan on standing while loading, make sure you set it up so your press is at eye level. The same for setting while loading.
Nothing ruins a good loading session more than a sore back from bending over all the time to see what you are doing.
Make sure you mount the press where you have plenty of room left on the bench for working (loading trays, small boxes, etc.)
The sturdier you mount it, the better, sometimes it takes a good bit of force to pull a rifle case out of the press.
My presses are mounted to my bench with drywall screws. I haven't had any trouble so far, and if a I decided to "remodel" I can zip them out with a cordless drill.
If you think it out, all the way, you should be able to set yourself up with little trouble.