I dont think you can download anything on the internet to your ipad, so the chances are slim to get a virus, apple just doesnt allow it. There is nowhere for your download to go, i.e. No folders to store it, nowhere to execute any programs either. All executables , or rather apps, must go through the app store or itunes, which are strictly reviewed by Apple.
I think if safety is paramount to you, the closed nature of apple is about as safe as you can get.