You'll want something that supports high speed sync. Basically, that black "curtain" you see is the shutter. It happens because the flash and shutter are not synchronized.
Remember too that in flash photography whether you fire the flash first or last does matter. If you shoot skate with second curtain flash, you might end up with a slight OOF streak behind the subject (the flash freezes the action in this case and can look pretty cool). With High Speed Sync, the flash simply fires multiple times lighting the entire frame and avoiding the "black curtain". Firing in HSS, you won't get massive quantity of light because the flash fires multiple times (in other words, you're not going to get multiple 100% flashes) but you can use less power.
Whether you use flash or not is irrelevant. What matters is your shots are properly exposed. Me personally? I'm not a fan of crazy dark backgrounds and nuclear subjects--it gets boring because that's how everything gets lit (or so it seems).
Regarding bursts and full power. Be careful. You can damage the flash when you use it continuously--they aren't designed to fire like that.
Here are a few hints on the subject of HSS