I've only ever heard good things about the V-Sprint stuff, but would definitely get the sealed bearing ones. You might also want to look at Halo Aerorage / Aerotrack (I'm not sure what the difference is) - these are pretty popular.
@Butters started
London Fixed Gear and Single-Speed is a community of predominantly fixed gear and single-speed cyclists in and around London, UK.
This site is supported almost exclusively by donations. Please consider donating a small amount regularly.
I've only ever heard good things about the V-Sprint stuff, but would definitely get the sealed bearing ones. You might also want to look at Halo Aerorage / Aerotrack (I'm not sure what the difference is) - these are pretty popular.