I run el-cheapo Scosche RCAs next to my power wire...no noise. Don't worry that much about RCAs, just get some cheap ones from Wal-Mart and you'll be fine; it's the grounds that really cause problems.
from my own experience, subs dont get any unwanted noise when you run the RCAs down the same side as the power wire. however, it does matter for mids and tweeters.