There are a load of points raised in that post mate, I'll try & clarify a couple of them... First of all "power".
I know what you mean when you say power, but it isn't the same thing as power in HiFi speak.
What you are really after isn't in fact more power but in fact more "loudness". When you're choosing amp & speakers, to get a feel for how loud they will be, you need to look at the speakers efficiency (measured in dB).
A speaker's efficiency is effectively a sound level reading taken 1 metre in front of the speaker when it is being driven at one watt (a more efficient speaker will be louder for a given input than a less efficient speaker).
So if you have very efficient speakers, you can get away with a less powerful (in terms of output wattage) amp to drive them, and still get good loudness levels.
If you look at speakers, you'll see a lot of them quoting efficiency ratings of around 89dB. That's fairly typical. If you look around at a few more, particularly at the more expensive end, then you'll probably find speakers rated a few dB either side of that figure.
So why is it so important, well, check this out...
In order to increase sound output (efficiency rating) by 3 dB, you must double the output power of the amp.
So to get the same loudness level out of an 87 dB rated speaker as you get from a 90 dB rated speaker, you need
an amp which is twice as powerful
So... you're looking to buy an amp & speakers & you want more "power"?
Choose the most efficient speakers you can (that you like the sound of obviously) and drive them with an amp who's nominal RMS output power exceeds the rating of your speakers. Do that and you won't go far wrong.
Obviously the most important thing is subjective... you should just buy whatever you like best... but there is a science to how "powerful" the sound will be.
OK... EQ's... surround sound... presets etc. IMO just the sight of an EQ with presets or surround sound is reason enough to chuck your whole system over the hedge, but then I'm an arsehole, and that wouldn't help you much
They really aren't very nice though. They use DSP chips to fuck around with the sound between leaving the CD & exiting the speaker to "fool" your ears into thinking you're in a concert hall, or a nightclub, or listening to a really really expensive stereo... right... ugh... Usually what they actually do is add chorus, reverb & echo in varying quantities to whatever sound they read off the CD or whatever. Basically, what they do is deliberately fuck the sound up for no good reason whatsoever (most likely to try and hide the inadequacies of the stereo which in fact sounds shite... you be the judge... switch all the effects & shit off & see how it sounds then).
The "proper" answer here is that any EQ or surround, or bass/treble controls are the work of Satan because they all fuck the sound up in one way or another and all amps should only have 1 knob for volume. That way what you hear will be exactly what's on the disc. Lovely. Except that half the time "what's on the disc" sounds fucking awful. (Play either of the first 2 Oasis albums with your EQ flat, then play Frankie Welcome to the Pleasuredome the same way and you'll see what I mean).
So they're a practical necessity in most cases. But all you really need from an EQ are Bass/Treble controls. Those are enough to allow you to sort out the varying quality of your CD collection so they will all sound reasonable, and at least they won't use DSP circuits to add effects & really fuck the sound up badly.
If I were in your shoes mate, I'd transfer all your music to your ipod & sling your current stereo altogether. Then go out & choose yourself a nice amp and pair of speakers. Then you'll be forced to listen to everything off your ipod, but at least it will sound decent... Or to put it another way, you'll be able to tell your good recordings from your bad ones! The beauty of separates is that you can then add stuff like CD player, tape deck etc. on to your system & build it up gradually as and when you get the cash.
But it's horses for courses. At the end of the day all in one systems are easy, and convenient & have tape/CD/Radio etc already built in. You pay for that in sound quality though... even with the expensive ones.