Hi,
You can try HikaMarket in our demo website :
demo.hikashop.com/
There is a menu "Other Features > HikaMarket" where you can access to the front-end edition part of the component.
HikaMarket is not yet a "eBay" like component. There is one missing feature to let the vendors receive directly the money from another customer.
So for the moment, HikaMarket propose more "marketplace" features than "ebay" one. But we are working on it.
About the uploading problem. I am quite sure that the problem was resolved and that it was a javascript problem in the website or a write permission problem.
As you can see in our demo website, we have a nice uploading system for images and product files. You can use "drag & drop" but it uses some javascript and sometimes, if there is a little javascript error from another part of the website (another component for example), the javascript process stopped and so, our uploader is not initialized.
We improve our system and add some "security" patch in order to try to initialize our uploader even if there is other javascript problems (and I can assure that our javascript does not have errors).
Regards,
Jerome - Obsidev.com
HikaMarket & HikaSerial developer / HikaShop core dev team.
Also helping the HikaShop support team when having some time or couldn't sleep.
By the way, do not send me private message, use the "contact us" form instead.