Nope, I would buy a static rope (no elongation when loaded) from a reputable rock climbing company. YOU DO NOT WANT A ROCK CLIMBING ROPE. They cost alot of money. Static lines is what you are after, which is MUCH cheaper, and doesnt elongate when loaded. Make sure they are CE (Triple Sig) and fat enough for your prussik knot to latch onto.
Ill try to find you a link...