I have a four dog stove and can no say enough good things about it. I got the water heater that hooks to the side. I do not think that I would get the water hater again.
I am with everyone pushing the 4 dog stove. I got a 3 dog for my Alaknak 12x12. Unlike some of the other stoves, it has a steel plate welded between the fire and the stove top so the flame is pushed forward then back to the stove pipe. This eliminates most sparks coming out of the stove pipe.
Our group out grew the tent we had planned on this year so I said screw it and ordered a 15x18 Davis wall tent and their largest stove. If my wife doesn't kill me, I should be invited out west for years to come.
Another vote for 4 dog stoves. I've used a 3 dog model in an 8x10 tent for years down to sustained -40s and been warm. They have an internal stove damper that makes the heat and flame travel in an S shape before exiting the pipe. This gives you more heat and a hot spot on the top of the stove for fast cooking or water boiling. This spot will warp easy if the stove gets red hot. The stoves are truly air tight.
A pipe damper isn't just to control burn. It also reflects the heat back into the fire box to increase efficiency of your burn. I'd highly recommend one. They also help stop sparks.
For water, I think the tanks are a pain. Just get a big pot on top. The warming shelf is nice on the dog stoves. Gives lots more space and various heat zones for cooking and melting snow or heating water. The tall legs on dog stoves also offer a place for wood storage. We recoat ours each year with stove paint and it still looks great after six years of use, besides a small warp here and there.