I will be in Paris from the beginning of June until mid August. My schedule will be pretty open through June and so I am hoping to make several weekend trips, or even 4-5 days trips, to the neighboring countries. In July I'll be more tied down to work in Paris, but might still be able to do a couple of weekend trips. In August I will have two weeks of travel time and I am planning to make a circuit through the U.K. given that I have friends there.
In a situation like this, what is recommended for train tickets? I know that you need separate rail passes for the UK, but is there any pass that makes sense for just a two-week period? As far as travel from Paris, I definitely want to see some of Germany and the Czech Republic. I'm thinking of skipping Rome in favor of seeing Venice and the caves in Slovenia. I'd also like to see some other regions of France and maybe Spain.
Any suggestions for the type of rail passes to get that will make this easiest/most affordable?