Long runs like this don't have very good resale value--that can be good for you if you are patient and watch the used market. I'm biased towards Audioquest. I've tried a lot of cables, and always seem to go back to AQ. I have long runs between my crossover and ML 20.0 and Krell KMA 160s. I used to have an AR pre-amp. I would recommend the AQ Emerald (now discontinued) if you can find a pair in that length. I'm using Lapis and Diamond--but wouldn't recommend either of those with the AR. The copper Emerald will give a slightly fuller and richer sound. My AR was a little on the lean side and sounded better with Emerald than with Lapis. I have not tried LAT cables, but Sean has been great asset to this site--so I would seriously consider his advice as well.