I'm with Fatparrot that there isn't any real difference which set of posts you hook up to. O'm sure that, if there is a prefered arrangement, the owner's manual will mention it. As to bi-amping using the speaker's existing HF and LF inputs (passive bi-amping), you'll need two amps of equal gain and the easiest way to accomplish that is to get two of the same amps.
Let us know how it works out for you.
Regards
Jim
Let us know how it works out for you.
Regards
Jim