The 500mW diode was used by an LPF member to replace the diode in that exact laser..
Personally I recommend getting the 1W diode and running it at half-power to extend the lifetime and allow for minor tweaking of the power output.. doing this will ensure a long life and some real toughness when it comes to being modulated. Here's a link to the 1W: http://cgi.ebay.com/1000mw-808nm-la...53141QQcmdZViewItemQQ_trksidZp1742.m153.l1262
IIRC those modules don't require the c-mount to have a fast axis lens, so you can ask snoctony for one without the lens. I think he should be able to do that for you..
REMEMBER TO MARK THE POSITION OF THE ORIGINAL DIODE ON IT'S MOUNT BEFORE YOU REMOVE IT. If you don't do this it will throw the alignment off a lot when you put in the replacement diode, which will be pretty frustrating to correct...