AARONMADLER,

As you pointed out, this is a highly subjective issue. Nevertheless, since your speakers are 20 years old, or so, I would look for a center speaker that has a similar voicing as your main speakers. That being said, there are people who believe that the center speaker is the most important speaker where movie watch is concerned. That I believe, depends on how accurate/anal you want to be. I do subscribe to this philosophy myself.

In any event, I believe that the Model 990 has the ability to spead some of the center channel information to the fronts by going into the "Surround Config" setting and changing the "Center Width".

Hope this helps.