If you will be hiring a planner that would be first, because they will know the venues better and even have discounts on some. Venue #2; Video #3 and Make up last
If you chose not to hire a planner than Venue, Video and Make up.
I think that venue is the kind of service that plays the biggest role in the wedding, as well as it's probably the hardest part to get amazing venue. you can check and choose your perfect venue on http://www.wherewedding.co.uk/ where you can find amazing places from alla round the Europe!