Two good resources for this might be the Your System Saloon (where many people have posted their specific system descriptions and some feedback) and this old thread about what speakers and amps people have paired up with their 990's. The 990/7500 combo should be pretty neutral - the bigger question is probably going to be which speakers you like more, as speaker preferences are a pretty personal taste. I haven't heard much about the Energy speakers you mentioned, but I've heard good things about the Ascends.