Since you're not planning on upgrading to gigabit service, my recommendation is to go with the Cat 5e. You could get the Cat 6 and use it with your current setup, but you probably won't notice much if any difference (aside from the price). Technically the Cat 6 is more reliable, but the difference (if I'm remembering correctly) is something like 2 error bits (with Cat 5e) compared to 1 error bit (with Cat 6) based on a 100k transfer. I regret that I'm not at home to verify these numbers. I'll try to remember to look them up on Sunday after I get home, for verification purposes.
