I live locally (about 10 miles away) and know the area very well. You say you are travelling by train - I presume somebody will be able to give you a lift to Barham as it's out in the sticks with no train station etc?
Do you want to stay in Canterbury city centre, or a country pub/hotel nearby? If you let me know I'll come up with some suggestions for you. Strangely, there aren't that many hotels in Canterbury itself, and some are quite pricey, so an idea of the budget would help as well. If you're thinking country pub you might need to think about how you're going to get around - there are some lovely villages around Barham and Canterbury, but getting around could be an issue.
Simon