We've a local mill here, a pretty big one, that does white pine.
http://wardlumber.com/facility.asp gives a look at their mill, which can handle logs up to 36 inches diameter.
They produce white pine T&G flooring, in quite wide random widths, for those that want the antique farmhouse look. I've seen it at up to 28".
Not exactly random, but made in 2-inch increments, so that you've a chance at end-matching when needed. Ends are plain cut, not "endmatched with T&G." and lengths are long.
What precautions should one take in using ultra-wide white pine flooring?