The bottom shims are how the knuckle is centered, the top ones are how the pre-load is set. Do what Duffil said as far as the bottom ones.
This place use to sell the SST but I could not find it. I even put in the PN and it did not come up. PN is 09606-60020 so they may not be making them anymorehttp://toyota.spx.com/index.aspx
Your best bet is to get the "Super Seals" from Marlin. They are a lot more forgiving then the stock axle seals and well worth the extra cost.