Ok so Im looking into different pistons for when I go to rebuild and Im wondering what differences there would be if I bored the cylinders .020 over, .040 over, .060 over. Im guessing that Ill at least hone the cylinders, but are there any gains to doing this or going larger than stock?

You should only overbore for what will bring the cylinder back into specs, some times only a hone will be needed.
But if the cylinder is oval shaped, it might take .02 - .03 to get it round again.

Now, if you're boring it to get more displacement, you can get some, but you can only go so far before you'll need sleeves.

if your going to have a machine shop bore it out, go big, nothing less then 40 over, because it does add displacement. obviously you dont want the walls paper-thin, but going 40 or 60 over will add hp!