Long RCA interconnects

I have a Benz Micro Silver MC

OK that's a healthy 2mV output so the phono stage will be outputting 1.4V which is a good signal and should put you in as good a situation as you could hope to drive that long single ended run. If you had a .3mV output (i.e. typical low output MC) things might be more problematic -- anyway good luck!

Don't know of options but 18 feet is very bad news sonically.Good luck though.

Just got in a pair of Kabeldirekt 20 feet pair to test out. Sounds amazing. Just for peace of mind I'll probably end up making my own 'audiophile' interconnects but cool...and it looks like I really need 15 feet or so.

So eventually ended up making my own interconnects....12.5 feet length is actually sufficient, I overestimated the initial length.  Went with DH Labs Silver Sonic II cable and KLE Copper RCAs...total parts cost $200...all silver plated wires to interconnects...sounded fantastic at initial listen.  Not a cable believer at all, Pink Floyd's 'The Wall' never sounded better through vinyl though...but who knows, may be the $20 Kabeldirekt sounds the same as well, I just can't be bothered to test. Wanted to make a shielded silver cable and here we are.  Highly recommended. If I wanted to buy it, it'd probably cost $800 - $1200, you figure $200 (parts) + $400 (labor) + $600 (marketing + other overheads) = $1200.