rMBP & ext. monitor minimal cable clutter

What you need is a thunderbolt 2 dock. they aren't cheap but they give you the option to have all you external HDD's keyboard even mouse and monitor set up with a thunderbolt cable as the only connection to your rMBP.

Amazon is possibly your best bet they have a fair few...

http://www.amazon.com/s/ref=nb_sb_noss?url=search-alias=aps&field-keywords=Thunderbolt+dock

 

I posted this in a different thread the other day, but I thinks it's relevant to you for some comparison notes. I think samuelsan's suggestion is a great replacement for the "landing dock" mentioned in my setup.

My office setup was:

Stand I used is mStand : http://www.amazon.com/Rain-Design-1...1437312423&sr=8-1&keywords=rain+design+mstand

Landing dock: http://www.amazon.com/LandingZone-E...&qid=1437312578&sr=8-14&keywords=MacBook+dock

Monitor: http://www.amazon.com/Dell-S2415H-2...id=1437312698&sr=8-4&keywords=dell+monitor+24
[edit, I would go 25" after studying a bit]

Keyboard: http://www.amazon.com/Das-Keyboard-...d=1437312873&sr=8-1&keywords=das+keyboard+mac

Apple's Magic Trackpad.

The only one hassle I had each morning was plugging the mag lock back in (the landing dock doesn't have a firm holder for the connector). I don't consider that a true hassle, so no buyers remorse.