if you just want a CLS slave flash, the sb600 does everything that the sb800 can do (yea you lose 2/3rds of a stop....no big deal), for quite a lot of money less, especially now that the 800 has been discontinued. If you've got the D200, you can use the built in flash as a commander so don't even really need a 800/900 on camera as a commander unit.
The key thing with cls basically is just to make sure that the sensor is pointing in the right direction. Other than that, it's a really good, dead simple system to use. And as you said, if you ever are doing something that needs the range, you can use your skyports and just rock it manually.