Hi Rizzo,
What you need is just a
coax cable with RCA terminations. I use this variety in my home theater. It's cheap and does the job quite well. (this link is to a 25' length, obviously buy the length that fits your situation). Another good cable manufacturer is BlueJeansCable. Either one will be fine for you and as long as you are not making an incredibly long run from receiver to subwoofer, you won't notice an audible difference between either company's cables.
The
Y-connector is something like this... it just splits one RCA connection into two. One cable will go to your buttkicker, the other will go to your sub.
Jason
