for me, I got a 8x burner, as most people do, and I always use the +r's, because they ALWAYS play in any of my dvd players. the -r's don't at times. either way, it would be fine, just 4x would take longer, but not by much.
Just remember, don't do other stuff whle your burnin'! especially if your gonna go 8x.
let me know if that helps!
indestructable