Caterer wanted

I can't recommend one , however you will find quite a few listed here http://luxembourg.angloinfo.com/af/371/luxembourg-catering-caterers-cooks-and-chefs.html

Best thing is to have an idea as to the sort of thing you want eg: Sit down /Buffet / Canapes.  From experience of catering this sort of events you also need to consider if you need help serving/ clearing and washing up as this is not usually the chefs role.  I would get a few quotes and compare what is included.  Most private caterers will have sample menus and even be able to let you taste some of the items before you decide on the menu.

Hope this helps a little and hope you have a great get together.