Some older canvas pyramid style tents did/do use external poles, but I'm not sure how they fair in the wind compared to conical tents with an internal pole. For ME the modern silnylon tipi has three things going for it--------it's floorless, it's very wind resistant, AND it's wood stove compatible. If you intend to use a wood stove (highly recommended) then the stove and pipe are already in the middle of things and a center pole is no big deal, and is actually be handy to hang things on. Getting the right sized tipi is the better solution to floor space IMO. If torn between sizes, go bigger.
