Thanks again for everyone who has given input on this thread, I appreciate your advice.
I love my 50L and want to invest in primes. As such I ordered the 135 f2 last night, so should have a few weeks to play with the lens before our holiday.
If I could afford it I am so tempted to go for a 35mm too, and take that and the 135. I would have nothing in between but it would make me get used to these two lenses. If not I will take the 50L and the 135L.
I unfortunately live on a small island and we only had one camera shop (Jessops) which recently pulled out, therefore I can't get access to try out lenses before I buy. I have a couple of friends into photography but have my own idea of lens choice. I agree the 24-70 II would probably be a good choice but as mentioned want to stick mainly with primes if possible.