We would like to offer our hosting clients graphics in the SiteStudio website builder gallery. These are graphics they can choose from to insert into their webpages.

I have many CDs with thousands of graphics, but they are not licensed for this type of usage, so can not be used. Outside of taking our own pictures and uploading them (yeah, right!), is there a place we can purchase graphics for the use of all our clients? Right now, our gallery is empty, and I would like to remedy that.

I don't know how this type of use would fall under their TOS, but you can check out: http://www.sxc.hu/browse.phtml

Free stock photography. BUT, since you are a hosting company (?), and you are offering these to your clients, I don't know if that would fall under "reselling". If it does, then it violates their TOS.

Not sure what they allow, but http://www.istockphoto.com and http://www.gettyimages.com are good.

You could try http://www.gograph.com
They will provide a co-branded clipart gallery for your site.