Forgive me.

Forgive my ignorance O Masters of Sound and Fury. But other than sound quality, are any other factors significant when matching separates from different manufacturers? For instance, output voltage or input sensitivity or input impedance of a pre-amp when connecting to different corresponding values of another brand of amplifier? Any technical issues, simply sound, or nothing to be concerned about?
Sometimes component compatibilty is an issue. For instance, some preamplifiers do not like to see a low (20K ohm or less) input impedance in the amplifier they try to drive. A poor match can result in poor sound, and incorrectly be ascribed to the component(s). One solution is to buy an amplifier with a high input impedance so almost anything can drive it, or buy a preamp that is very tolerant of driving low input impedances. What specifically do you have in mind?
I forgive you, for now, heh heh. You really need to read "The Complete Guide to Highend Audio", and a few back issues of Stereophile. OF COURSE THERE CAN BE LEVEL AND IMPEDANCE MISMATCHES, so try to compare the specified outputs and inputs of the components you are considering, if possible. And again, you can't just figure out what will work best ahead of time. It always takes at least some trial and error. Good luck!
Thanks for responses. I have nothing in mind yet. I'm new to all this, and just exploring possibilities to power my Genesis APM-1 speakers. Next step is a good amplifier, but the specs are so varied on input impedance(~47 kohms to 100 kohms) that I just don't want to paint myself into a corner re: pre-amps etc...
Audition amps and preamps at the same time, or try a beefy integrated like the Plinius 8150.
just have fun this hobby will drive you bonkers first and foremost go by what sounds best to you
No, nothing else is important. It _does_ help to be aware of these issues, such as impedance mismatches. But all problems will result in bad sound, so your ultimate judge is still your hearing.
You can do one of two things, either educate yourself on the nitty gritty of electronic equipment, or you could avail yourself to a good dealer. I would start with an amp. Find one that truly matches the Genesis, then work upstream. It's not as hard as some people will make it, but a mismatch will definitely be audible. As a rule of thumb, tube equipment will require the most care.