I had a really nice one. If you can swing it, I recommend getting one with 6" walls, and there is a classification system for insulation and winter-worthiness (is that a word?). I'd go with the best I could find, even if you had to live with paint or cabinets you hate for a while.

I like shingled roofs, too. But it may be because of the hideous wind we have here.

I did get my breaker box upgraded, too, but mainly because there were four females living in it with all the electronics that go with hair styling, music, and computers.
I also put in the best septic system I could and went quite over the top with the leach field. Again, four females, three of them teens.
I loved mine, and miss it still. I will no longer ride/work the pasture that borders the section it was on.
I hope you find a perfect one for you! :D