RCA analog cable choices

I will preface that I am not looking to spend more the $500 on a pair of RCAs. I want a decent pair of RCAs but I have too many other expensive hobbies. Less is even better.  I am sure there is a point of diminishing returns somewhere in the ether - way above my price point - but I am sure there is some version of diminishing returns somewhere in the $200 - $500 price point... so given the limitations of my own system - I am looking for that sweet spot. No sense in spending more than I have to or want to spend. 

I picked up a Cambridge Audio: MXN10 and the DacMagic200M for a decent price and need some decent RCAs to go to my preamp. All in my entire system is less mid fi comparable to what is out there... but its my system. :)

I don't have a dedicated  2ch system yet. But working on it - my current system:

ATI 200 X 7 AMP
MARANTZ 7704 preamp
b&w CDM9NT - KIMBER 8TC speaker cables
Cambridge Audio MXN10 AND DAC200M

It was a system that was dedicated to home theater use - but we honestly don't watch many movies ever.  So I really am migrating to just 2ch ... I am looking for a stop gap until I can invest in a real system with real money but for now -- 

I was considering the following: 

kimber: pbj, hero
tributairies 6 or 8 series
BJC - LC2


I know there a dozen others that are out there - small custom shops etc... 

Given my system - anyone have any input or thoughts on where I should 'start'. I was leaning hard for the kimberr pbj and hero just because I have experience with Kimber products - and I am happy with the result -- but I am open to suggestions. 

Note:
My room acoustics are not ideal - hardwood floors with large area carpets. In great  room with kitchen and couch etc... have drapes etc.. but not professionally tuned by any means.

Thanks in advance.