Yes, it's NMEA. My concern was only with wiring and voltages and such.
Well, looking at how this guy made his own serial cable without any max233 like components, I'm guessing it is using normal RS232 signal levels.

In any case, you could always leave the TX line from the empeg (i.e. RX on the gps) disconnected, the NMEA parser never sends anything to the GPS anyways and if the GPS is really using 5V outputs that won't harm the empeg either.

Python works on windows just fine, that's one of the reasons I used it instead of writing the parser in C.