Long Run From Computer to Stereo


I have Echo Layla 24/96 soundcard with analog outs. The analog outs are 1/4" outputs that are going to require a rather long run over to my stereo. That length will be approximately 35-40 feet to get it situated properly into my tube preamp. Obviously i will need to get the RCA adaptors for the preamp end. But can anyone recommend such a length of decent quality cable for such a set up? I don't expect it to be the best quality but just something decent. I don't even no where to begin looking for such an animal in 1/4" runs of that length.
Right now i am running guitar cables(which sound decent) to my studio monitors but they are only 20' long and i don't know of any cords longer then that in music stores?
Thanks!
seekburk
Well i had gone ahead and ordered the long run(37') of Canare GS-6 from Bayoucables (with G&H gold 1/4" outs and RCA plugs in) to run out analog over to my stereo. I am not set up for balanced operation unfortunately i don't believe unless i am missing something. I admit that I am ignorant about that but the soundcard outputs I am using are not xlr and neither are the inputs on my preamp. I will post my thoughts and feelings about the sonics going unbalanced analog after I have a chance to have a good listen. He is a one man operation so they will take around two weeks to arrive. But his prices are great and from what i have read his build quality is top notch. This seemed to be the best way to go for me at this time logistically and financially(cables only $100 assembled and delivered) so i am excited to get them and to hear what my computer audio will sound like running through my main system.
If indeed there is some shortfall, I would suspect it might be in terms of voltaage drop. Depending upon the output of the audio sending device. mONARCHY aUDIO MAKES A DIP. (?)

This unit increases the voltage output to around 5vac up from the nominal 2+ many sources output. it has digital outs and ins.

I recall one person who said they got one for just such an instace... a very long cable run under similar circumstances. It worked quite well for them. Just a thought to consider.
You may run into issues with single-ended cables. Correct me if I'm wrong, but the Layla has balanced 1/4" outputs -- i.e. TRS (tip-ring-sleeve). For best results, use a TRS-XLR cable, and if you need to, use a converter to change your +4 dB XLR signal to a -10dB RCA signal next to your amplifier / receiver.
Sunjitwhy, i am not sure if the outputs are 1/4" balanced or not. They are 1/4" though. I did receive the long cable that i ordered from Bayoucables a few days ago with the 1/4" and RCA ends. I guess it took some time for that cable to break in because initially it sounded very harsh and the digital glare was bugging me big time. But things have certainly seemed to have warmed up and i am also certainly not losing any HIGHS with the long run. Sounds pretty good so far and i am pretty satisfied at this point but still listening and evaluating. I have about 20 hours on them at this point. The WAV files sound really good but still not sure that they are superior sounding to my CD players audio. But as of yesterdays listening they are very close and i was suprised of the detail i was hearing with the WAV files. Just something about them that i seem to be able to hear things clearer. But that may come at the expense of dynamics it seems but that gap also seems to be narrowing the more i listen.
What i would like to know is, could i possibly achieve better results completely bypassing my soundcard(however i do that?) and instead use a wireless USB-NOS/DAC(paradisea+ for example) setup? Or something similar? I do not have firewire out.
thanks!
Thanks for your response by the way Sunjitwhy! The cable that i am using, that was just built for me, is Canare GS-6 cable, which i believe is used for microphone cables. So i am assuming it is balanced? My other question is, i have the ability on my Layla's mixer to either use the +4 db(balanced?) mixer or the -10db(unbalanced?) section. Which one should i be using and should i be turning the volume up more on the Layla's mixer and using my preamps volume for adjustment? There is no converter on my cable and it is just terminated with RCA's on the one end going into my tube pre. I am currently using the +4db section of my mixer and that seems to sound pretty good. I'm still playing around to see what sounds the best. But just looking for optimum sound and dynamics out of this setup. If you can offer any further advice i would greatly appreciat it!