you can find a lot manufactures in www.alibaba.com, but you need to buy a lot of the same item in order for them to ship.
Unique items are always the best to sell anywhere and ebay is no different, antiques and even some of your old junk that you have lying around might be a good place to start but look at whats already out there first you might think that that old book is rare and unique until you do a search for it on Ebay and find that there are 250 of them selling or I should say listed from .99 to $9.99
I agree with Blitz, sell something that you like. Once upon a time i sold nail polish from revlon and it was fine. Ebay is good for electronic products too.