The Cooler Master RC690 sucks up a lot of dust, I'd recommend dusting at least once a month if you don't use any fan filters except the stock ones. With the stock fans it's not quite as bad, since there are only three of them, but it still requires more dusting than most cases. The case only comes with one LED fan as the intake, and while it's not too garish, I didn't care for it. I don't like LED fans in general. The only light I really like in a case is some nice UV cold cathodes, which help the accents glow and are very toned down. The RC690 isn't the best case for illumination with the stock side panel anyway, the only places illumination will escape are through the fan holes, and while there are a lot of them, they don't really look that great. The stock fans are also very quiet (and pathetic in terms of airflow), you shouldn't need to consider turning them down unless you're a serious silence enthusiast.
SLI is an enthusiast venture for the most part, I wouldn't recommend it given your budget and needs. Better to just get another single high-end card once the 8800GT/GTS isn't performing as well as you'd like. SLI mid-range and low-end cards are NOT a good replacement for a single high-end card. They suck up more power, don't always offer consistent performance, and will add a lot of heat to your case.
And no I don't care about noise since I use headsets all the time I was thinking of a control panel to turn off led lights not the fans themself : P
Okey so I'm gonna stick with 8800s