Keith,
Don't let the audiophiles stamp your EQ idea into the ground. It's all hogwash. Every band, mixer, record producer uses them. Everything you have ever listened to has been equalized by somebody at some point. No reason you can't too, to your tastes. My interest in EQ is to attempt to overcome deficiencies of circa 60's and 70's recordings, including those reissued as "digitally remastered." If they don't go back to the original multi-track tapes (which is a lot of work and very expensive and results in a different mix) the sound will be no better more often than not. I am convinced that broadcast radio has taken to EQing their recordings for broadcast to give them a consistent sound or feel. I hear things that have obviously been improved upon (and that any objective listener would agree with) but aren't commercially available. I would agree with others that today's recordings generally do not need EQ so it is better to focus on the other components if that is the problem.
There are scores of equalizers out there because, as I said, everyone, except apparently audiophiles, uses them. You can get an analog or digital dual channel 1/3 octave (33 band) EQ that is suitable for stereo. Some of the most recent digital EQs are equipped with digital I/O (a definite plus when working with CDs) and the best of them have memory features where you can fine tune your adjustments and retain them for later use. Look at the Alesis 230D or Behringer 2496, both in the $400 range. If you don't want to preserve the digital path, analog EQs can be had for a third the cost. But without the memory, you cannot save your settings. As you probably know, if you stay in the stereo realm, an EQ is readily incorporated into your system using the tape monitor in/outs. There is nothing equivalent I am aware of in multichannel A/V receivers but then, as I said, I cannot see doing much EQ with todays' recordings, which would include true multi-channel SACD, DVD-Audio, DTS, etc. However, if you really wanted to do it, there's an 8 channel Alesis DEQ830 that presumably could handle 5.1 and higher formats. But with all the unfortunate but necessary DAC conversions going on, it might sound worse, even without much EQ.