Hi Jimm,
Your post is over 2 years old now, so I assume that you have found a fix for your seatpost issue already.
To get a longer seatpost, you need the seatpost from the international version of the qicycle, which is longer.
Note for other Qicycle EF1 owners, the seatpost design is unique and proprietary. This is because the seatpost is not perfectly round, there is a indent. Therefore, it is not able to use other seatpost replacements (as shown in the teardown).