Imac A1311 compatible optical drive?

Hello everyone, I'm having burning issues with my iMac, is out of warranty now and I'm sure is not media related. I have try all the available brands and it won't burn even under Windows 7. I tried to clean it with compressed air and I got no results. I'm not in the US so I cannot take it to a repair center and local authorized centers are a rip off (I use to work at one) I wanted to ask you what brands and models are compatible with my Imac? I have read that some drives won't fit, and there are some really expensive parts arround that cost $400!!!! thats almost the price of a Mac mini.