>>>"If you have 2 upgraded power cables to use where is the the best place to use them?"<<<
You may want to look at this from a different perspective ... most power cords are built in various configurations and designed for specific applications
High current amps and power conditioners generally benefit for larger gauge conductors that can deliver high bursts of current un-impeded
Low level sources and pre amps will benefit from cables whose construction can deliver constant ... non varying ... rock steady ... linear current ... the clocks in our digital components do no like swings in current as they use it for timing ... varying current = swings in the clock's timing = bad mojo
Analog components usually don't require extra shielding as they generally don't balloon RF as a by product of their operation into the surroundings
Digital components usually benefit from shielding as they do tend to balloon RF into the surroundings as a by product of their operation ... which can then couple to the other components in your system
IMO you need to determined what type of power cords you have
...(>>>"If you have 2 upgraded power cables to use"<<<)
... and how and where their design will work best with which one of your particular components
The other side of the coin and an opposite approach is to look at the component's requirements in your system for a power cord and then purchase a cord that best matches that component requirements
You wouldn't put a set of 16x32 ripple wall Drag slicks on your VW Rabbit or a set of premium snow tires on your Bugatti Veyron
I viewed your system and by the looks of your home ... your probably driving the Veyron
I feel cable / component matching is the most critical followed by positioning
If you have the right cable component match ... Then IMO wall to power conditioner will benefit all components followed by source to power conditioner as any information lost at the source can not be recovered down stream
Big power amps tend to have very robust power supplies and storage capacity that seem to respond less dramatically to power cords ... but you still need to mate with the right designed cord
Power cords can not improve the in coming current but they can definitely severely degrade it when mismatched
>>>"I really am too lazy to do hours of testing"<<<
"Education is what you obtain when you read the small print ... Experience is what you get when you don't"
Understand your products design and function or you will be out in Left Field batting Flies