Almost all jQuery version are available on Google, but you don't need to download them, you can simply hotlink to them. Which is often better than downloading them because many visitors to your pages will already have then cached. For the latest version of Simple Gallery, jQuery 1.8 would probably be good, that would be:
Or you could do:
If you want to host your own copy. Using a browser other than IE, just go to one of those links and then copy the code that appears in the browser.