Sounds like you already have a pretty good handle on things, but here's my tuppence..
Good oaks hew nicely
Tulip poplar hews very nicely
white pine hews pretty nicely
good logs of maple, hickory, and walnut are ok to hew
avoid elms, sycamore, horn and hophornbeams.
I would only try the lesser used species if you get a kick out of that sort of thing.
If you want the hewing to be as efficient as possible, get clear, straight extremely green oak or preferably tulip poplar logs barely big enough to get the size timber you need.
