You for the most part correct.
A 2 conductor pickup simply has Negative and Positive.
A 4 conductor has both, with the addition of 2 more wire leads that allow for coil tapping & phasing, as well as series/paralell switching.
Your 2 conductor is wired up so the those additional 2 leads are concealled in the bobbin tape and are factory wired as series, ie; one coil into the other in series.
You can wire up any 4 conductor wired pickup as you would a 2 conductor, you just need to follow the manufacturer's instructions on soldering the additional 2 leads together and concealing them in either shrink wrap or tape so that they do not contact any other conductive surfaces. It's quite common for many people whom have purchased pickups with 4 conductors to do the latter and not take full advantage of the additional varieties of switching options. So for simplicity sake, if the pickup you are looking for is only available in 4 conductor wiring, fear not, just follow the instructions on wiring it up, you'll be fine.