There are software solutions that will allow you to do it its time consuming and doesn't quite look right. You can have your edit software just export the frame rate you need to.
We shot some stuff for a company in Iceland and we couldn't get it to look quite right so we sent them the original footage and let them convert it.
But in the today digital world, what the real difference between a PAL and NTSC video file ? Probably the fps (in case you didn't pick the 24p for both). What else ? It shouldn't be so hard to convert.
I was even considering buying the NTSC ver of the HCM150 versus the 152 (or EU one) since a part from powering it the differences should be very minimal. With the NTSC you can even do some better slomo
Any comment from the wiser guys on this board ?