I used to work somewhere that sold the Intercomp timers. Great quality, heavy duty unit. These days though they're a bit cheaper if you shop around, i.e. http://www.summitracing.com/parts/ICP-360050/
Like GTRKat, I'm looking at the Performance Boxes, as it appears they're a lot more versatile for club level motorsport, because you can use it as a lap timer or 1/4 mile timer. It can also give you a lot more information on your car, which I thought might be useful for a couple of projects we're working on.
They're readily available in Aus for $650, and about the same price to import, so not cheap. I haven't read anything that's made me make a decision one way or the other.
G-TECH Pro looks like a similar thing slightly cheaper: http://www.summitracing.com/search/Brand/G-TECH-Pro/?keyword=g+tech
If anyone has any experience with these kinds of things it'd be great.