You ask good questions, but I'm likely to steer you toward what I prefer, not necessarily what you want or need.
For example, I would not use a pellet stove that needed electricity, though I have seen one model that doesn't.
Instead, let me point you toward some folks who are very well informed about woodstoves generally.
They have a lot of good comparisons between models, some advice for dealing with the blackened glass problem, and in general if you want a woodstove they will have the details.
http://www.chimneysweeponline.com
They are located in Washington state, so you could conceivably buy from them. But they shouldn't be tempted to pressure you, or blow smoke rings around your concerns, like a local stove shop might that cared more about the sale.
I have lived with rocket mass heaters for about 5 years now, and I wouldn't go back. Probably saves me $500-1000 a year in heating bills / fuel, even though we live in under 1000 square feet. And it's way easier to run and more comfortable than the woodstoves and fireplaces I've experienced elsewhere.
Not sure why heating hot
water is the deal-maker with the
rocket stove. It's not something either of your existing stoves does, is it? Hot water adds a lot of complexity to a system, and complexity means more things can go wrong.
You might look at purpose-built stoves with that function for one of your stoves, and something with some thermal mass storage or self-operating capacity for the other.
-Erica