I don't know of the suppliers you mention personally, but as for bonanzle. Still a very new site really, but it is free to list, so it's costing you nothing by having your items there.
I would suggest taking advantage of the free platform and stocking your booth with plenty more products, the better the selection you have to offer, the better your chances might be of getting a sale.
Bonanzle also has a good forum that you can get on and do a little promotional work, within the right areas of course. Bonanzle also has some useful marketing tools, easy upload to Google Base for example, so make sure you are making the most of what they do offer.