You are correct, 2000 and 2001 were issued for circulation, and 2002-2008 were NIFC. Personally, I have a 2002 and a 2008 NIFC Sacagawea dollar (I can't remember which mints they are from). One came from my sister, and the other was found in a bank roll.
In 2009, the government started the new "Native American Dollar Program" to go along with the presidential dollars ("Presibux"). These new coins will honor a different Native American contribution to our nation each year with a new reverse design, and will have the lettered edge like the Presibux. I happen to like them quite a lot.
You can order these Native American coins, along with the 2001 Sacagaweas and the Presibux from the US Mint online store, at face value with no shipping charge. You won't find any silver, but they're fun to spend and get reactions from cashiers! I spend these and $2 bills regularly.
If you want to know more, check out smalldollars.com
It's not my site, but it's the place to go for info about dollar coins.
Have fun & Happy Hunting,
Nick