Tesco finest goosefat roasties are very nice - I tend to rub them with a bit of extra oil, for extra crunchy deliciousness. But if I were doing a ham, I would cook it the day before, and serve it cold, with baked potatoes and salad (all nice and easy to do on the day).
You will want a minimum about 3-4oz/75-100g of ham per person (more, if you want left overs for sandwiches over Christmas) - so for six of you, I would go for at least a kilo joint, maybe more. There are some lovely recipes where you cook the ham either in coke or in wine or in ginger ale (the flavours permeate into the meat while it cooks), and then you let it cool, take off the skin, score the fat and put a glaze on (something like treacle and brown sugar and spice), then finish it off in the oven, to get a lovely glaze on it. I am going to do this with our Christmas ham, and it is going to be our Boxing day supper, with baked potatoes and salad and chutney (I might have a go at making the chutney, but I will probably just buy it - much easier!).
Smoked salmon pate and toast would be a nice starter, as would smoked mackeral pate. I've also had a nice blue cheese and pear pate - poached pears, cooled and cubed, mixed with blue cheese and cream cheese. I wouldn't serve a big or filling starter (soup is particularly filling, I think).
Do you want a hot dessert or a cold one? You could make a mincemeat strudel - buy filo pastry, and lay sheets of it out to form a rectangle about the size of two A4 sheets, put longsides together. Spread with mincemeat (bought is absolutely fine), and small cubes of eating apples. Roll it up carefully (if you lay it out on a sheet of baking paper, you can use this to help you roll it up), and brush with melted butter, then bake. Serve with pouring cream.
Alternatively, Nigella's Clementine cake is absolutely delicious - and it is really easy to make - you gently boil the clementines for a couple of hours, let them cool, then throw them in the food processor, blitz them, then add the other ingredients and blitz again, then pour into a deepish cake tin and bake - it is the most delicous, dense, slightly damp cake, and is lovely served with whipped cream as a dessert. And you can make it the day before.