Re: Who''s living on what??
I've been living on an Albin Vega for going on 4 years now. I agree with some of the other posters here, that bigger isn't necessarily better and that if you're going to live on a boat at all it will be easier to adjust your lifestyle (possessions) than to own a boat big enough to hold everything you want. I can't stand up straight inside my boat, but that is only occasionally annoying.
For paring down your possessions, you'll find that a lot of us liveaboards go through the same process. First, you put ALL of your stuff from your landlubber life into either a storage unit or a relative's basement. Second, each time you go there to get rid of stuff, you'll pick up an item and tell yourself, "No, not yet." Then, the next time you go there, you'll pick up the same item and tell yourself, "I'm never going to use this again, and anyways, by the time I ever would, it will be cheaper to buy a new one than pay storage for a couple of years." I've done it with decent quality oak kitchen dinettes, stereo, etc. It's not an overnight process because you are changing the way you live. It helps, though, to anticipate the eventuality of it.
The good general rule of thumb is to get the smallest boat that's big enough for your purposes.
Oh, and I do live in a marina, so in the winter I plug in to the dock for my oil-filled radiator heater.
Just remember, the more you want your boat to be like a house, the more you have to pay and continue to pay (slip fees, more heat / AC, etc.).