Advice for Subwoofer Balun at back of room?

Hi I wanted to get some recommendations for doing the following:

Run my single-RCA (subwoofer) out of Denon Receiver --(to)--> L/R Audio klipsch Subwoofer.
I currently have a single subwoofer cable going to a Y-Adapter to my subwoofer.
I also have (2) Cat5E cable runs from plate near receiver to back of room.

Now I want to connect Sub to back of room, so I bought a pair of Niles C5-HDDA Baluns. The Niles C5-HDDA is a CAT-5 Component Video and Digital Audio Balun.
C5-HDDA image

I setup like this:
[Receiver] <-- (single Subwoofer Cable) --> [C5-HDDA Digital Audio connector] - [RJ45]<--(Cat5E)--> [RJ45] - [C5-HDDA Digital Audio connector] --(Single Subwoofer Cable)-->(Y-Adapter Cable)---> [L/R Audio Connector on Subwoofer]

I believe the Niles I bought on eBay did not work. Seller stated New, but one was scratched and I did multiple tests to rule out Niles Baluns but everything I tested pointed to them not working.
- I made sure cable wiring was using T568A standard as Niles manual states.
- I used a Cat5 ethernet cable tester and verified good cables.
- I ran brand new cable (tested) directly on floor to test again and still didn't work.
- I tested (store-bought) 6" patch-cable (cat5e) to eliminate distance and still didn't work.
- Then to verify my equipment was all working I bypassed the Niles Baluns and ran cables directly to subwoofer and subwoofer worked fine.

*I also have a networking (IT) background and have ran ethernet cable in past.

Questions:
[Receiver] - (sub cable) - [Audio Balun] - (cat5e) - [Audio Balun] - (sub cable) -- (Y-Adapter) - [Subwoofer]
This should work fine correct?

Is there a preferred Balun to use here?
A. Digital Audio Balun
B. Standard Audio (L/R) Balun with (2) Y-Adapters ?
or
C. Coax Balun
D. Component Balun and use any one of the single cables to pass audio through? (not to sure this would work but guessing in theory it sould)

*Also I really do not want to replace my 2 Cat5E in-wall jacks for a Wall Plate Balun so prefer to use a small balun at each end.
Edited by FuRoSh - 12/14/12 at 12:32pm

First thanks for you response.
SPDIF port?
The receiver has SW out, Balun has Digital Audio IN/OUT, subwoofer has L/R IN. Sorry don't know which port exactly you're referring to. Is SPDIF same as any I just listed?

Denon AVR-3808CI A/V Receiver rear image:
http://www.audioenz.co.nz/2008/images/denon_3808-rear-l.jpg

> Connecting directly?
Are you suggesting connecting the Cat5 cable to sub using RCA connector?
I opted to go with Cat5E (multiple-purpose) cable w/ Baluns rather than running long Coax (single-purpose) cable to back of room or higher-end $costly$ Subwoofer cable that I needed about 150FT (Up wall, across ceiling, down wall) to back of room.
Edited by FuRoSh - 12/14/12 at 2:09pm

Sorry if this was misleading, I actually moved my subwoofer back by my receiver to verify all my equipment was still working to bypass baluns.

Thanks guys! I submitted my info to MuxLab to find reseller but can you recommend a good source to purchase from?
Google shopping shows several online stores like 123securityproducts.com