Hey guys I am in desperate need of some fast advice.

I am currently building out my living room, and thinking of the follwoing settupL

Sony HT-DDW900 receiver and speakers with HDMI IO's
External DVD,
VCR,
comcast cable box
Panasonic PT-AX100u DLP projector (no screen just, but thinking of painting the wall) comments suggestions will be appreciated.

and would like to control all of the above with a Harmony 890 remote.

The big question is can I extend the IR transmiter from the standard 6ft to 20ft?
I am thinking of splicing the cable and using a 22 or 24 gauge twisted pair or cat5 cable for the extension. (I would solder and will use heatshrink).

*** When I checkd with Logitech's Tech support they said extending the IR emiter is not a supported application, and would void the warranty, but my question is will it work, or has anybody tried it? ***

Can you recomend alternative if it will not work.

Thank you!