Older thread - if I was going after a 5K system, I'd start collecting "keepers" to build upon later. Oppo's earlier mentioned at 1K now have 32-bit DAC's and rated Class A, plus Oppo has great support for newbees. Next, I'd determine whether I wanted near field, mid field or far field "sound". Multiple crossover's and multiple drivers can sound a bit congested at near field. That being said, most near field set-up's are two-way speakers with one crossover. At mid and far field, bigger drivers and often multiple drivers/crossovers become more common because the sound smoothes out at distance.
If you know a multichannel active speaker line sound that you like, say the Paradigm Active Series, this may be a savings over separate speakers, amps and more cables. I'd consider buying the two active smaller rear's first, and use them initially as your front mains as a mid field 2-channel system. Later, I'd add a matching musical sub and the larger front main's and center.
For non-active speaker's, I'd also consider the Oppo, the earlier recommendation of a adequately powered integrated amp or "regular amps fed directly by the Oppo (use the Opps volume control)", and add the speakers. This approach builds a surround system off the original purchases. Good topic for new buyer's.