Well of course it is muscular, but yet with finesse. We are talking about a Kiwi amp here, not something from West Island (known as Australia to you). North and South Islanders (Kiwis) are typically just so.
We of course do not enjoy such stratospheric incomes as Americans do, so we can only upgrade one from your list at a time. But fortunately Plinius gear is dirt cheap in NZ and that helps us have enough money left over to buy American cables and things when our currency, the Pacific Peso, lurches upwards on some whim of the international financiers (such as confusing us with Luxemburg - also tiny and insignificant)
Despite this I have managed to try a decent range of ICs and speaker cables with the Plinius gear and found the Kimber 1130 ICs to be very nice, as well as the Wireworld Gold Eclipse speaker cables and the Kimber Select speaker cables - but they obviously should do at the price, and I would find it hard to recommend them as value for money.
The value for money choice would be Coincident ICs, being wide open and fast enough to let the Plinius shine without breaking the bank. The Alpha Core Goertz MI2 Python speaker cables work great at very reasonable prices too. So too does the equivalent Goertz silver cable - but at a much higher price obviously (meaning a delay on that new mistress).
I have had the combination of Coincident ICs and MI2s in the system and the result is fast, musical and very balanced.
AC power cords are a bit of a problem down here as few of the US-made cords can fit our pathetic plugs (all made in West Island these days) and only some of them are safe for 230V. But I can say the SA102 likes a chunky power cord and I use Synergistic Research, and it seems to not like the Shunyata cords I have much - goes all lumpy in the bass. The CD-LAD likes the BMI cords, or more accurately the BMI on the CD-LAD is required to balance out the characteristics of the Synergistic cord.
I have written extensively on Audiogon on my views about isolation. But in summary I use a welded steel rack that is spiked to the floor and which supports its shelves on spikes. Then I use Neuance shelves between rack and component, and use no fancy footers at all - despite trying perhaps a dozen or so different varieties. The Plinius feet seem to be ideal for the Plinius.
I find the Neuance to be quite a remarkable product - being light (so that it will not store energy), rigid (so that it releases the energy quickly) and damped (so that the energy is not released in a narrow resonance band). Who cares why - it just sounds both neutral and very fast - usually you only get one of these, if you are lucky, but at the expense of the other. And performance for the dollar is excellent.
Now did you realise (as I have come across Americans that get confused on this) that the word Kiwi does not refer here to the fruit. Here we call that thing a Kiwifruit, and I guess we shortened the name for export purposes to make it easier for foreigners to spell. The Kiwi is many things here, such as a member of our national rugby league sports team or just a New Zealander, but its origin is that it is the name of one of our cute native flightless birds, which some say shares much in common with males from these shaky isles, since it eats, roots and leaves.
But whatever you may hear about our silly left-wing politics and our pointless, ludicrous and terribly amusing anti-nuclear stance, you Americans are very welcome to come and spend your money here anytime. What you would save on buying a SA102 here would pay for the return business class air fare.