I would recommend Furutech FP-Alpha-3, Acrolink 6N-P4030 or Neotech NEP-3001 for amps.
The Furutech FP-Alpha-3 is a 12awg, 49 strands, OCC, Alpha [cryogenic and magnetic] treated, unshielded cable, available from Partsconnexion.
The Acrolink 6N-P4030 is 10awg "purity stress free" stranded 6-nines copper, also unshielded, and is cryogenically treated by VH Audio.
The Neotech NEP-3001 utilizes 10awg individual UPOCC conductors for hot, neutral, and ground, and an aluminum/mylar shield and is available at VH Audio.
For source components, I would recommend a shielded cable such as Furutech FP-3T, Neotech NEP-3003, or Oyaide Tunami.
The Furutech FP-3TS20 is a 14 awg, 56 strands, OCC, Alpha [cryogenic and magnetic] treated, and shielded cable, available from Partsconnexion. The FP-3TS762 is a larger 10awg version with bundled fine wire strands (this larger cable has won more awards according to their website).
The Neotech NEP-3003 utilizes 13awg individual UPOCC conductors for hot, neutral, and ground, as well as a tinned OFC copper braided shield (but no treatment). This is available at VH Audio.
The Oyaide Tunami utilizes a 5.5 sq. mm (slightly bigger than 10awg) PCOCC conductor core and 3 layer shielding. This is available at VH Audio.
If you want to push the limits, get the Neotech NEP-1001; Neotech's top-of-the-line 9.5awg power cable made with pure OCC SILVER conductors and a tinned OFHC braided shield with drain wire. The price at VH Audio is $999.99 per meter.
Personally, I highly recommend the Furutech FI-25 series plugs and IEC's, which are made from OCC copper and Alpha treated, but many also swear by Oyaide and I have a couple of those in my system also.
In my situation, I would probably use the Acrolink 6N-P4030 on my amps (if I didn't already have Isoclean cords) and the Furutech FP-3TS762 on my source components.
As you can see, there are many great choices for making highly competitive PC's out of bulk cable and top quality connectors.