Reddit mentions of FosPower (15 Feet) 2 RCA M/M Stereo Audio Cable [24K Gold Plated | Copper Core] 2RCA Male to 2RCA Male [Left/Right] Premium Sound Quality Plug

Since you're in a coupe I would recommend removing the rear speakers from your equation and setting up an active front stage. Here are some suggestions for your front stage:

Front stage option 1:

• 1pr Sound Solutions Evil 6.5" midbass - $100
  
• 1pr Sound Solutions Evil 1" Tweeters - $90
  
  Front stage option 2:
  
  
• 1pr Tymphany NE180W-04 6.5" midbass - $180
  
• 1pr Tang Band 25-2176S 1" tweeters - $60
  
  Here is a good 5 channel amp with the needed crossover capabilities that won't break the bank:
  
  
• NVX JAD900.5 - $230
  
  Here is a good amp kit and other needed stuff for installation:
  
  
• NVX 4 gauge amp kit - $70
  
• 1x FosPower 15' RCA - $15
  
• 2x FosPower 15' RCA Y adapter - $22 (needed to split the front stage to all 4 channels)
  
• 100 foot NVX 16 gauge wire - $30
  
  Here is a subwoofer option that will sound clean and low:
  
  
• 1x Audiofrog G12D4 - $200
  
• 1x QBomb 12" sealed enclosure - $70
  
  Cost for front stage option 1, amp, and sub:
  $827
  
  Cost for front stage option 2, amp, and sub:
  $877
  
  EDIT: Replaced out of stock SSA sub with Audiofrog model

ideal, optimal connection setup? https://www.amazon.com/dp/B016QVZEZ2?psc=1

previously owned cheap RCA cables, needing new ones, saw these.

so i am in the home of audiophiles - how would You connect your amp & speakers for the best possible sound quality. these are high quality speakers that vary in quality based on how they are connected - as i have heard, would not hurt to invest if needed..?

open to all possibilities! amazon preferable, currently have them on the wall just waiting to be connecte