Most of that tone comes from the distortion on the amp. Randy Rhoads used a marshall stack and used the pedal to clean boost the sound. This means to have the drive on the amp turned up, but the gain on the pedal turned down, so it doesn't add any distortion.

So if you don't have a great amp, I really can't help ya that much. I'm sure there is a way to get a great tone out of just pedals, but I don't know it.

Good luck man!