The two heads I gig with are a GK MB 500 and a Genz Benz Shuttle 6.0. The GK is surprisingly loud and clear for a 500 watt head - it has earned a reputation for punching well above its weight class. Although the Shuttle is more versatile than my MB 500, it isn't quite as top-end loud. But that just means that it's terrific for when I'm playing indoors (through a pair of 2x10 cabs) and the GK has the edge for when I'm playing outdoors without PA support.
The Shuttle has a single tube in the preamp that can be pushed into a mildly wooly sound with the gain cranked up, but it can also be warm and smooth. The three filter switches on this head are all surprisingly useful, too. This includes a "mid-scoop" switch that cleans out some of the honky aggressive personality I get from my custom P/J without my overall tone getting overly scooped and lost in our mix. Long story short, it actually sounds good (the "Contour" dial on my GK on the other hand...

).
There is a fan on my Shuttle and while I wouldn't call it loud, I can hear it when I'm practicing at home at very low volume. That being said, it's not at all a nuisance for me. I've heard louder fans on other heads. I'd say this Genz Benz could be worth checking out if you spot one near you. They also made a Shuttle 3.0 that could be useful, but the 6.0 certainly is not overkill for playing in a smaller setting.