We really enjoyed our stay at Kong Keo guesthouse ! It's a family run businness and Mr Kong, his wife and his brother are very friendly and helpfull ! The tour they offer is pretty nice too and if you choose the option 2 with the included dinner you'll really enjoed the food. It cost about 140.000 kip. My grilfriend and I got a nice room (quite basic) for 50.000 / night.
You can spend the evening next to a fire drinking beers (10.000 kip) and ask to your hosts to play some guitar.
Just so you know, if you want to take the night bus to Hanoi (at 2 am) they can book seats for you but it doesn't take 12hours as everybody seems to think. It's more about 20 hours !!!