miniDSP with separates or Arcam SA30 or NAD C658 plus beefy power amp?

I'm mainly trying to get a Dirac capable 2.0 or 2.2 channel system going.

Sorry I misunderstood!

Concerning the P429 amp, it is never a good idea to buy a multi-channel amp just to bridge it.  For one thing, it reduces the ability for the amp to handle lower impedances on speakers.  When bridged, you need to make sure your speaker is 8 ohms and does not drop down low.  Many speakers nowadays will drop down to 3 ohm impedance in certain frequency areas even though the speaker is listed as an "8 ohm speaker".  Second, you are compromising the design of the amp and forcing it to execute in a "work around" mode.    You're much better off looking for a higher power stereo amp instead.

I'm hoping you realize the Arcam is an integrated amp, so you don't necessarily need an external power amp for it.

Another thing to be aware - the HT bypass modes will typically bypass ALL PROCESSING in the preamp/integrated, including any Dirac room correction.

I'm running the 658 into a Wyred For Sound St500 MkII. Couldn't be happier. I can recommend the 658 without reservation.

I have a minidsp 4x10 HD in my system.

A minidsp is a great device that is completely quiet and as far as I can tell with no audible degradation. It will give you a much greater array of ways to improve your system's sound than you will ever get from room corection in an integrated device. Having the ability to tweak a midrange band by +2 db or to null out a peak will make a much bigger difference in performance than the pretty well inaudible effects of another A/D D/A step.

@auxinput:

Concerning the P429 amp, it is never a good idea to buy a multi-channel amp just to bridge it... 

Thanks for the insight.  The reason I thought the P249 would be best is because it is also Arcam for pre-power sensitivity matching purposes, and it's the only one I see other than the other multi channel HT amp they have.  The P429 is intended for HT also. I'm not sure why they don't have a current 2-channel oriented amp for critical listening.  Does that mean they don;t think you need more thsn the 90 watts the SA20 has?  Or the 120 watts the SA30 is suppose to have?  I'm not against matching it with another manufacturers power amp.  The reason for more power is in my limited reasearch I've tentatively decided it proabably does help (especially with my KEF R3's which dip to 3.2 ohms at about 70 and 110 hz) to bring ou the best in clarity and transients with a solid amount of current available and the headroom a better amp could provide. 

I'm hoping you realize the Arcam is an integrated amp, so you don't necessarily need an external power amp for it.

I know.  I'm just a little hung up on getting more power and current from my reasoning above.  I'll run it without the external amp initially anyway.  The other reason for the outboard amp is I'm trying to upgrade my electronics for a future speaker upgrade to something in the KEF R1 range.

Another thing to be aware - the HT bypass modes will typically bypass ALL PROCESSING in the preamp/integrated, including any Dirac room correction.

Understood.  Although I'd like Dirac in my HT, I'm mainly wanting to implement it into my 2 channel listening system.  Actually, I'm kicking around the idea of just getting an Arcam AVR (or NAD AVR) with Dirac to keep everything simple but *most* of what I read opines a good integrated will perform better than a top line AVR for 2 channel listening.  In an ideal situation I'd separate my 2 channel and HT systems.