Hello listers,
thanks so much for all the info! The whole discussion about clocks that came up here has also been helpful to me in order to get a better understanding of why it is actually required, so thanks a lot for that as well! I think the best solution for me would be the package from http://www.olifantasia.com/drupal2/en/node/12
This includes a modified USRP 1 with the Clock Tamer and includes all required components, so sounds like a suitable option for me. It's a bit more expensive than just purchasing the single components, but with my limited electronics skills, I'd say it's better to be safe than sorry :-)
Thanks again!