I am reproducing this box...

http://tinyurl.com/hjr43


....or at least trying to (take note of both images, the top becomes
clearer). Anyway, I am using 1/2" stock all 'round. That being said,
and my complete inability to transpose spatial images, how would I
select a router bit to make an edge like the one around the top? The
top will be 1/2" as well.

I guess on a broader point, are router bits purchased and used
according to the thickness of the stock? I look at these in the store
and it seems to me they need to be used on 3/4" or thicker stock or the
bearing on the end will be above the edge of the wood.

Am I looking at these wrong? They are too expensive to just pick up a
few and experiment.

As always,
Thank you.