Singlespeed & Fixed Gear - I wanna get started

So I wanted to get a mountain bike but really wanted the simplicity of a single speed bmx type. I knew I would feel awkward riding a trick bike being almost 30, so imagine my happiness when I browsed the aisles and saw a beauty - a kinda cheap Specialized single speed with disc brakes. To my pain, I discovered that it was only so cheap because it was last year's model - big friggin deal. Oh, and it was a 17" as opposed the the 19 that the sales guy thought I would need (I'm 6'1"). Nobody seems to stock turnkey 19" single speeds.
Long story longer, can anyone help me in my search for something under 400? I want to keep my labor part of it pretty small and would prefer to buy local in Austin. I know that's asking a lot. Thoughts? Obvious beginner here, so no noob flames.

Thanks,
RG

I ride a smaller MTB frame (6'3" and 17" frame), but I like a smaller bike to throw around on technical trails. Another option is a 24" cruiser, if you want to go with a BMX bike.

It depends on what your LBS stocks, but you can check out the MTBR reviews at http://www.mtbr.com/reviews/singlespeed/ .

There's a few people on here that ride the KHS. The Monocog is a good ride and uses a BMX hub in the back, instead. The IRO Mia (http://www.irocycle.com/fixedgearandsinglespeedbikeframesfromirocycleinc/id104.html ) looks like a pretty nice little singlespeed, but they're new, and I haven't read any reviews yet.

Flame! Flame! For under $400 I think your very limited in terms of what's out there. Even the Hardrock SS is about $500-600.

Check out the Bianchi USA website... the S.A.S.S. or the Cannondale 1FG... they're both expensive too though, but you'll get an idea of what is available.

Ok youse guys: here's what I have so far in order of reviews read. I know it's a bit more than I want to pay...:

1. Redline Monocog (chromoly frame, rigid forks - I'm 210 lbs - is the responsiveness enough to offset the ride comfort/frame weight?)
2. Haro Zero - looks pretty - pros/cons? (discs, some suspension, weaker frame)
3. Specialized HardRock (discs, some suspension, weaker frame)

Any horror stories, etc?

These are the three that seem to come up a lot. I know there's no substitute for trying them out, but my little kid fear is that the redline will feel a lot heavier coming off a jump. I'm a big fellla so this might be a dumb point, but it still lingers. I don't plan on beating the hell out of the bike, but I don't want to bend something soft under my dark beer belly.

Thanks for all the help so far. This weather really has me jonesing.

RG