Hey Tonto2k, Welcome!
Which motor is best depends greatly on what your goals are. You stated there aren’t many hills where you live, and you are interested in a single drive so I assume high speeds is not your thing, so the smaller motor would seem more in line with what it sounds like you want.
That said, you don’t have to use all the available power of the larger motor. If it’s putting out more power than you want, you can limit it in the VESC software. Therefore, I would suggest going with the larger motor. Cost difference is most like negligible.
FWIW, I’m converting my Landyachtz Switchblade to an electric board and am using a single 6374 sensored motor with a 12s battery (2 6s li-poly 10,000 mAh). I’ll also be using a Ollin VESC with a new Enertion Nano-X remote (if it every ships).
Best of luck on your build!