Ebay, Amazon or Alternative Affiliate Program?

Hi All. First post here and as I can see there are plenty of experienced IM's here I figure this might be the place to get some advice.

I run a musicians website and forum which has been going in various forms since 2001. Until recently I have not considered monetizing the site in any way but since I want to spend more time working on the site now I need to generate some income from it.

Have tried Adsense of course but that is pretty much a waste of time. The returns are so small as to be almost not worth having.

Now I am looking to other forms of revenue building such as joining an affiliate network, the question is, which one?

I have read that many people here prefer Amazon and I have no reason to doubt it is a good affiliate to sign up with however I am thinking of our site visitors and the sort of things they are likely to click on. The majority of our members would be far more likely to be searching out used musical instrument bargains than shopping for something new. Given that is the case would I be better going for Ebay over Amazon?

Are there any other suggestions that would have the potential to give a reasonable return?

Traffic to the site has always been good although certainly if I were to actually advertise the site, which I never have, we could do better than the 30/40,000 visitors per month we currently get.

Any advice much appreciated.

Thanks

Saul