It sounds like you've already made up your mind. I think the Englander 30nc is a great choice. I have been using one for four years and I love mine. As a matter of fact I installed a craigslist stove first that required an 8" flue. If I had installed the Englander in the first place with a 6" chimney it would have been cheaper than the used stove with 8". Live and learn. At least the Englander seems to work fine with the 8".
As far as 12hr burn times, you probably won't see that. More like 6-8 hrs of decent heat and then 2-4 additional hours of holding enough coals to start another fire depending on wood type, wind, etc. I pretty much can feed mine 3 times a day and keep the house comfortable.
It has always burned whatever I threw in it but for a hot, long lasting, low smoke, low burn you really need well seasoned wood.