Heating, Cooling, Plumbing, gosh the choices

Well, today my brothers inlaws all arrived. My brother lives right by me and so it's really fun. They come down from New York every year for about a week. Anyhow, they already had me over and had me bring pics of the lakehouse to show. Right away they started asking me how we're going to heat and cool it and when will we get the plumbing in ? - I had no answers. lol I do know that the first thing we'll have to do is get the house wired. When we'll get started on that, I have no idea. My parents had thier cabins for years and years without any electricity or indoor plumbing, I hope it doesn't take us that long. haha, oh well. It's still the most beautiful place in the world and we love it just as it is. I would however absolutely love any advice on heating and cooling options. Ideas anyone?