No, the OEM tool kit does NOT come with a valve shim tool. Just the usual assortment of worthless pseudo-wrenches made from cheddar cheese.
I would add that you can get metric feeler gauges at any Pep Boys or Advance auto parts. They only go down to .04mm (.03mm is the minimum clearance), but this is not a problem -- if the .04mm gauge won't go in, I put in the next size smaller shim, then re-check.
Do NOT try and do this using feeler gauges or a micrometer marked in inches. That's a sure way to drive yourself nuts and make expensive mistakes. Chinese-made digital calipers that work quite well and read directly in mm are widely available for $15-$20.
Here's an expample:
http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=47257
I wouldn't order from Harbor Freight's web site because their shipping and handling charges are exorbitant, but if you can find a Harbor Freight or some other purveyor of Chinese tools nearby, this is what you're looking for.
I'm lucky enough to live 20 minutes from CRC2, but when I was building up my shim collection, I would figure out which ones I thought I needed, then buy those plus the next size smaller (valve clearances tend to decrease over time). After a while, I had painlessly built up a pretty complete collection. I haven't needed to buy a shim for a while.
Suzuki dealers generally no longer stock the shims (none in Indiana do, anyway), but sometimes the local independent shops have a kit. Most will want you to purchase, at $5 - $10 each, but a few will trade if you're a good customer.
Valve clearances tend to decrease, and the exhaust valve clearances decrease faster than the intakes. You're supposed to check every 4,000 miles. I whip my GS850 like a rented mule (lots of high-rpm running on interstate highways and back roads twisties), and most of the time I only need to replace one or two shims every second or third valve check.
Lastly, replace your valve cover and breather cover gaskets with silicone Real Gasket:
http://realgaskets.com/files/motorcycle.htm
These are reusable for a lifetime as long as you're very careful never to overtorque them and you don't wash them using solvents. Simply wash with hot water and dish soap, pat dry with paper towels, clean off the cylinder head and valve cover surfaces, and reinstall.
Realgaskets seal much better than OEM, and they make valve checks much easier and less expensive.