Look at the letter below and choose the best form from the alternatives given

Dear Andy and family,

I’m just writing (to say / saying) thank you for (to have / having) us to stay last weekend. It was very kind (of / for) you. We all had a really great time and look forward to (invite / inviting) you over here next time.
Tom and Alice really enjoyed (meeting / to meet) the children next door to you and keep on (talking / to talk) about all the things they did together. It seems that they have found some friends and they are all interested (in / by) similar things.
Thanks again for the wonderful barbecue you prepared. We were lucky (to / for) have such good weather. We really enjoyed (to go / going) to see “Star Wars” together with you all on Saturday night.
Anyway, now we’re back at work and thinking (about / to) the next time we meet. When would you like (to visit / visiting) us?

See you all soon,