@tvrgeek
Your comments about stock Belden cables being hard to beat is interesting given all the theories, marketing hype, and exorbitant pricing for "audiophile" cables that either by measurement or listening tests have not been uniformly proven to provide significant (if even audible) sonic improvements. Belden cables (among other professional type cables) are mostly used to process the music we listen to and the equipment we use for playback includes many feet of mostly basic copper wire that is used in transformers, speaker voice coils, and other components.
Belden makes some compelling stock cables and I believe it would be interesting to listen to their bulk/stock cables compared to much more costly "audiophile" cables, assuming the Belden cables were similarly terminated.
For interconnects, the Belden 1800F you mentioned uses foamed Polyethylene insulation and braided copper shielding, and should perform well as an interconnect, either RCA or XLR. If this had been specifically designed for the audiophile market, it seems they might have used their High Conductivity Oxygen-Free Bare Copper (OFHC) wire instead of their Bare Copper (BC) wire, which I believe is tough pitch electrolytic copper (99.9+ percent pure copper at 100% IACS).
For speaker cables, instead of the 5000 series which uses PVC insulation, I would suggest the line of Belden speaker cables recommended by Galen Gareis for those who want a less expensive option to his Iconoclast cables. Those options all use OFHC copper and are insulated with foamed Polyethylene. The line includes the two conductor 1313A (10awg) and 1311A (12 awg), and the four conductor 1312A (12 awg) and 1310A (14 awg) cables, either of which can be constructed in a star-quad geometry resulting in aggregate gauges of 9 and 11 awg, respectively.
I find it interesting that Belden’s upscale Iconoclast line does not include power cables and instead they recommend cables from the Belden Audio/Video (BAV) line including Belden’s 19105, 19106 and 19107 stock cable (high-flex 10, 12 and 14 AWG BC conductors) with upgraded connectors.
I am too far down the road with cables to go back and buy/try the Belden cables discussed above but if I were starting over, knowing what I know now and having experienced what I have related to cables, I would definitely use the cables listed above and save my money for component and speaker upgrades where I have always heard much more significant differences and improvements than with cables.