Accessing Legacy versions of JQueryUI and Themeroller
You can rebuild the quick access links at the bottom of their site to use the version you are looking for.
http://code.jquery.com/ui/1.8.10/themes/base/jquery-ui.css
http://code.jquery.com/ui/1.8.10/jquery-ui.js
You can see the release history on wikipedia to see which version of JQuery pairs up with the release.
You can access prebuild supported themeroller themes for legacy versions here
Google CDN Links for legacy JQueryUI
In regards to the custom JQueryUI and Themeroller package builder.
That is currently not supported for legacy versions. They are working towards a solution, but none currently exist. Reference