For transportation, you can try eurostar. www.eurostar.com The rate would be cheaper if you choose the train departs early morning or late evening...etc.
Thanks for all bk members' reply. Had found a link to reserve ticket while visit another 討論區, I think it is more convenience for booking. Just for your information as below:-
www.voyages-sncf.com/leisure/fr/launch/home/
Click the little UK flag and Viola, u're at the English page. The web site is not very user-friendly, make sure u got the names of the station correct as some of them are very similar to each other but could be miles apart.