How do you amp your system?

Well, if your 2 channel amp doesn't give you enough and you are OK with biamping the Kappas, then perhaps adding another 2 channel amp and using it along with the old 2 channel amp in a biamp set up should get more volume out of your mains.

The Yamaha AVR would still be driving the center and 4 surrounds+rears. (Again, adding a monoblock for the center remains an option if the Yamaha can't handle your needs.)

The Kappas will be upgraded. One day...but they aren't biampable.

I've read about Parasound, ATI, Outlaw, Wyred, Emotiva....the options seem endless. There's even a used Krell KAV500 on eBay that isn't too far out of budget, and it's bridge able to 400wpc then when I add a center and upgrade to the PSBs which are biampable, then I could use two channels each main speaker with 100wpc and still have 100 for the center...or there's the 200wpc+ with a few other brands....

That's where I start to get lost, because of the amount of choices with no 'right' answer

Sounds like a plan.

As you say, there's no right answer.

I can only add that you may find yourself on an upgrade spiral that could involve buying and selling a lot of equipment. In the past I have found myself to be better off just jumping over a couple of go-rounds. (Less fun but less work and less expensive.)

I'm kind of thinking along those lines. I don't like the compromises my budget forces me into, and sometimes prefer to do nothing until I can afford what I want. I'm almost there now with the amp choice - thinking an ATI 2007 is where I should be, but don't have a spare $3K right now. Emotiva could still be an option, but is that compromising? If I go with (for example) an XPA5 and XPA3, leaving the one channel unused, and having 200W per speaker for $1700.00 list, would that be 'good enough', or would the extra $1300.00 up front eliminate the need for upgrading? It's the old question of would I be wondering if the ATI would have been a better choice? I know, there are no crystal balls, but that's where I am right now. Of course, that doesn't account for the option of a used older amp or two,....

I run 4.0, with the front L/R powered by McCormack DNA-1DeluxeRevA, and the surrounds powered by my Onkyo receiver. I probably will go 4.1 soon, with a powered sub.