I know this post is ages ago, but I just came across it via a google search.
LOL on above re: historic homes...and California. No disrespect here, because that info provided is sound, but LOL on what is considered "historic." I live here in NY...and we've refinished many floors from the 1800's and 1700's - earliest one is 1726.
Generally back then, it was much more common to find softer pines and wide plank and sometimes even face nails. All of this, of course is due to tools and "machinery" available back then. Generally Douglas Fir wasn't used that often then (at least not here)...although one house we did from 1735 had Douglas fir, but I think that was an addition prob in the early 1900's. Most in the 1800s have old pines...and multiple species. Not sure if that was due to limited supply, limited budget or things being done at different times, but generally a minimum of 3 different species (4 if oak was added later).
Here, in NY, we see Douglas Fir often, especially in homes from around 1900-1930's. In the later ones from this period (e.g. 1925-1935), we tend to see more oak in the more expensive areas on 1st and/or 2nd floor and fir on 2nd and/or 3rd floor.
Anyway, getting back to the original question, my favorite brand of water borne poly is Bona Traffic HD and favorite oil based is Duraseal. You can read more about this here: Best brands of polyurethane. http://theflooringgirl.com/hardwood-flo ... mmend.html