Speaker wire change

Considering upgrading speaker wire and would like to hear from people using Classe 25 amps running in mono, Classe cp-60 preamp, and Martin Logan Ascents, or simular equipment. Current wire is XLO type 5 bi-wire.
My preference is to bi-wire and budget is $1000 and will be buying used. My runs will be 5-6 feet.
What wire would you choose?
Personally -- not trying to start a big debate --

I would take the $1,000 and upgrade my speakers before
I would sink $1,000 into cables -- IMO, you'll see a
bigger improvement in the quality of your sound that
way. Do a test, try your system with upgraded cables
and then try it with upgraded speakers -- see what YOU
think -- trust your ears.

This is MY experience.

When I bought my speakers, the hifi shop had them wired
with speaker wire that had to be an inch in diameter,
with brick-like electronic boxes wired into them -- very,
very intimidating looking stuff. I took my speakers home
and they sound just as good with high quality 12 AWG
99.999% oxygen free copper speaker wires that I got from
an AV site. WWW.PartsExpress.Com

Same wide sound stage, same detail, same resolution of
microdynamics, etc.

I love having better speakers.

I won't be going back for the inch thick cables with the
mysterious "boxes" wired into them.

But -- hey -- that's just me.
Rsbeck, not a very popular position around here, but I agree with you. How much improvement does the original poster expect from speaker cables? The manufacturers and the insane audio press have done quite a number over the years convincing 95% of audiophiles that cables are "components" and that asking the price of a decent preamp or integrated amp for 8 feet of cable is par for the course. The magic that has allowed insane margins on cables is being put to good use by the equipment mongers pushing the sound of spikes, cones, bearings and racks. How many more ways are there to spell out the word "GULLIBLE". The best improvement in these last few months around my place is the purchase of a number of XRCDs and of SACDs. They actually reproduce music. Jsawhithlock, I would recommend you get a home trial for the cables to convince yourself if that money would be better spent on cables or elsewhere in the system.
this is the one area where i have been skeptical, and yet have been proven wrong. upgrades in speaker cables and interconnects have made significant differences in the sound of my system. (power cords have not, even different digital gear has made less of a difference). i went from MIT terminator4 (the cables with mysterious boxes), to BearLabs cables -- MAJOR improvement in transparency. like wiping off a layer of dirt. i have since auditioned a full setup of purist audio venustas cables, and it was almost as big of a jump up -- more transparent AND more weight to the music. it was noticeable the SECOND i made the switch, without "burn in", "settling time" or whatever else... obvious, immediate improvement.

looking at my system, my speakers look like the best place to upgrade, but in my room, listening at the levels i listen at, my martin logans are perfect. i can't think of another speaker that could work as well in this small space, and still give me that special quality electrostats give me. i've listened to much more expensive speaker setups, and i like the sound of my aerius. so why not get the best out of them?