Looking to custom build a bike primarily for local use, but also some touring. Been throwing around the M500/M510 and M600 and have been leaning towards the M600 because we want something that can handle hills well and it has the higher 45kmh limit (I believe 500/510 top off at 25). With this, we don't want it to be overkill on flats and have to deal with a lot of ghost pedaling. Typical riding probably 16-18mph/25-30kmh. Thanks very much!