Recommendations for upgrade from 5.1 to 7.1

Being still in the state of upgrade frenzy (I am finishing up improving my main stereo rig - see other thread I started about a month ago), I like to hear your suggestions for system changes and/or improvement for my den based HT system.

Please note:
Planned changes are marked between [[brackets]].
The mix of components are to blame because of regular upgrades in my other music systems, relegating older or less suitable components to the HT system.

Source:
Video: Sony PS3 for blue ray movies and DVDs, HTPC. [[Oppo BDP 103 after uprading my current Samsung 55" LED HDTV to a 3D model]]
Music: HTPC/Logitech SB Touch [[after market power supply upgrade]], Sonic Frontiers SFT-1 as transport, Benchmark DAC1 [[Eastern Electric MiniMax Plus DAC with DEXA opamps upgrade]].

Amplification:
Krell Home Theater Standard [[7.1 processor but which one?]]
Krell KAV250a/3 + KAV250a [[selling them and get a better value/money 5 ch amp?]]

Speakers/sub:
Fronts: Duntech PCL400 (Black Knights) with Cardas binding posts (used to have Snell B Minor as fronts)
Center: 2x Snell ICS1000
[[Snell AMC800 in wall planned for 7.1]]
Surrounds: Snell AMC900 in wall
Sub: 2x Snell PS10 [[Velodyne DD-10 or one Linn Sizmik on ASC bass base]]

Power Conditioning:
Shunyata Hydra 4

Cabling:
IC: Cardas Golden Reference for L/R/C, Transparent Music Link for SR/SL
NordOst Silver Shadow for digital
Sonic Wave glass optical cable from the PS3 to Krell HTS [[any need to upgrade this cable?]]
SC: Audience AU24e for the fronts and center, Belden in wall for the rest
PC: Shunyata Python from Pconditioner to wall, the rest on a mix of Cardas Quadlink and Shunyata Venom3

Isolation: Black Diamond Racing cones/pucks under most devices [[will try Aurio, Symposium]], hockey pucks under the front speakers and subs.

Room treatment: 6" thick 48"x 24" Bass Traps on the side and back walls, thick curtain behind the system and front speakers on the long wall (best placement for the Duntechs) for a 9' x 12' basement room with hard wood floor on concrete and a relatively low ceiling of 7'. Two 8'x 5' carpets to reduce the echo. [[corner bass traps, maybe an acoustic panel on the ceiling right above the listening couch]]

What is my weakest link?

Of course YMMV but appreciate any suggestion to improve this system and/or improve the synergy between components in general and for a 7.1 processor specifically, thanks!