Personally I think I'd go with Thor. Fem-cap is fairly usable and purchable w/ gold right now (I think), whereas Thor is unusable without Rag or IW uni. IW Thor and IW Cap both receive massive upgrades from those uni's but I feel that without the T3 upgrade on Cap, you would get more use out of the Thor uni.
Just my personal opinon and in full disclosure I don't have the IW Thor uni - I'm basing judgment solely on second-hand experience. I really don't think you can go wrong with either.