If you biamp, generally it would be a good idea to use identical amplifiers, if you have different amp's you may get a difference in the signature of the sound from the different drivers...
Well, I guess there are no rules, whatever works for you is good, but I actually believe biamping is a good idea .....
Next step could be to remove the passive crossover in the speakers and replace it with an active digital or analog crossover, that's not going to be expensive because you already got the most expensive parts already (amplifiers)........
Warranty on speakers, nonexistent once you get to that point, but It could prove to be great fun......
You would probably get even more dynamics and more transparency from the speakers when you remove the passive X-over
Actually I believe the greatest benefits come from utilizing speakers with no passive crossovers.... There's a lot of physical theories why this may be better..... I guess I'm answering something you never asked for