This is really a no-brainer these days.. today rope is available that will out-perform wire and NEVER leave you bleeding...
I think generally if you can pull the rope you choose through the masthead sheaves (and/or any other sheaves in the run) you should get decent service out if it for a while. There are some 'strictly wire' sheaves in some mastheads, but if you're pulling a rope-wire splice through now you may be OK.
The good non stretch rope is a bit pricey - count on $2-3/foot for the real good stuff. SD will chime in here with the specs, I'm sure!
You won't regret it!