Cable recommendations for my new (preowned) system...

Speaker Cables: I built my own using OFC Cat 8,

https://www.ebay.com/itm/174307181712

pick your length, pick your color, cut off the connectors, strip the eight strands, put pure copper spade/banana/.... connectors on the ends

I used RED and BLACK, made twisted pairs, taped every 3 ft. Order a bit extra length, twisting shortens them some, cut the lengths after you twist them.

(8 x 22awg equivalent to: 13 awg)

https://www.wirebarn.com/Combined-Wire-Gauge-Calculator_ep_42.html

spades/bananas/ ... : caution: pure copper, it could be pure red copper, you want OFC Copper, typical spec is 99.9999 pure. they will have a thin plated finish so they don't corrode. I use the type with 2 set screws, and they need to accomodate up to 8 awg to make sure your 8 twisted strands fit inside.

For interconnects, get a pair of Blue Jeans cables inexpensive interconnects.  They sound much better than the entry stuff from Kimber, Audioquest and all the others.  For speakers, go with the Canare 4S11 cables which Blue Jeans can make for you.  Very inexpensive and they will hit home runs with your equipment.  

Even if you don’t have a tight budget, Canare is a great place to start. They do take a crazy amount of time to burn in or open up so don’t judge them for awhile. If you want the next step up in my opinion look at WyWires Blue series or if you budget is more then look at their other series. I’d start with Canare first though.

Buy used. Definately check out 'Audio Envy'. 

https://www.vhaudio.com/products.html

I’m a DIY http://www.venhaus1.com/diymains.html. kind of guy and just can’t justify spending big bucks on cables. They also sell them assembled.  Great quality at a nice value.  Their connectors are nice quality but a bit pricey.   I have even found some nice quality all copper connects on ebay and amazon.  I prefer a warmer full sound so intend to go towards all copper with gold plating connectors.  Cheers!