I rocked a pair similar to this on my mtb and bmx, they were wellgo's. The wellgos are supper cheap and have replaceable pins, they hold up to a beating pretty damn good too. Dan's comp has em for 13 bucks.Give an Engineer an inch, and they'll measure it.
You can find a cheap platform at just about any bike shop. I rock Origin8 track pedals with HoldFasts and they're fine as long as you make sure the excess strap material isn't in the way. A lot less clunky and a hell of a lot easier to get into than most platforms.