Would like some help with what to buy? for 4-5k$

I currently have an onkyo tx-ds575x and some JBL surround sound speakers.. they are the size of bose speakers? and have a JLB 8? sub?

I have decided that I would like more? I cant afford 10-100k$ even though it would be nice? like I stated before, I can afford about 4-5k at the moment, I don?t really have a problem buying used stuff, as my buddies told me great things about this site, and to forget ebay and come strait here.. so that is what I am doing?

My buddies recommended a few brands to me? so ill put them out, and if any of you guys have any other brands that you know of or think I should look in to I would greatly appreciate it..

Also, I would ?like? to get a pre amp, and an amp, but I do not know if with my budget I can afford to do that? The 4-5k would have to cover speakers, receiver/processor and amp.. pretty much all the audio stuff..

I was told that the Ymaha RXV3300 was a good receiver, and also that oknyo integra line as well

Could I get those units, or something else, I read that one guy had a B&K on the forum? but I don?t know anything at all about B&K at the moment?

For speakers, I was told to look at.. Klipsch,NHT, Paradigm or Definitive Technology..

However for the speakers, I don?t know what specific models to look at?

Also, I wont be able to spend all of the money at one time, kind of buy as I go type of deal?

Any help would be greatly appreciated, I hope I have made my questions clear..

Thanks guys!