AM2 retention bracket for Zalman CPU fan

So I got a custom built computer a couple years ago, and now I've decided to install a Zalman CNPS 9700 CPU fan for my Asus M2N32-SLI Deluxe motherboard. The problem is that the bracket that the current cooling is mounted on isn't the right shape, and I was never provided with the stock AM2 bracket. The fan provides a LGA 775 backplate and bracket, but they assume that the buyer already has an AMD one. The current one being used is rectangular with a round hole over the CPU and no lugs to clip onto.

All I know is that I need an AM2 retention bracket (or frame or whatever it's actually called), and that it looks something like this, but there are many different models to choose from. I saw a couple Thermalright models that support certain Thermalright CPU coolers, but I didn't know if it supported coolers not made by that manufacturer. Is there one in particular that would work with the Zalman fan, or does it not matter as long as it's for an AM2 board? Should I try contacting Asus to see if I can get one?