You'll be fine running the stock chain/dampener on a VS/S1X/XP or similar cam. Like Bio said, you'd probably want to replace it every 50k or so miles.
You can also bump the idle up a bit to make it easier on the chain/dampener.
As far as the smog testing, you'd have to talk to a Cali person.
You'll get similar results with all of the above mentioned cams, kind of down to personal choice and pricing. Though quite a few people have put the VS in only to upgrade to an XP or larger cam. I personally like my Comp Cams 76-802-9 and have no complaints with it at all. Check around for any demods to see if you can get a good price on a used cam.
