As it's a communion why not use the church hall? There wouldn't be any issues then regarding deposits and worries of an uncertain future? You could then get in a childrens entertainer for the children? www.minizoo.org.uk - the animal man came to my Sons nursery and the children all loved it! The Tall Ship is a good venue and will certainly keep the children entertained. You'll be looking at £550 approx for 16 people to include entertainer and party box food. Or you can just hire the space and get in your own caterer. As for a caterer, take a look at www.thetreviexperience.co.uk Giuliano was the chef at Trattoria Trevi on Great Western Road (owned by his family)for circa 18 years. It was sold on and he's set up his own catering company. I have used them on several occasions, good prices, excellent food.