best solution for image uploading?

[eluser]mandril[/eluser]
Well I have to make a site for products selling... and the customer should have a panel for posting his products.. but he want to upload lots of pictures for a product and my aplication should store them and resize them to create a gallery.

Is there any problem if i create a folder for each product with the productID as the folder name ? I know it will be less than 10.000 products... but is this ok ? it won't hurt my ftp navigation or hosting ? The best place to store them in CI is the application folder ?

Anyone with experience dealing with this ?

Thnks a lot