Which Overdrive Pedal To Buy.. ?

Hey, I am planning to buy overdrive pedal. I am wondering which shall i buy. I already have Boss OS 2, MXR Fullbore, MXR distrotion +. But during i start to play guitar solo, I am not satisfied with it's sound. I play solo like Ne-Clical, shredding, lots of sweeps arpeggio, melodic metal. Like Children of bodom Symphony X, malmsteen, Kalmah,...etc....I also play zakkwylde solo, having pentatonic scale. But mostly about 80% i play Harmonic Minor, Minor Scale. For riff effect i m satisfied with fullbore pedal, but for the soloing i am not, lots of distortion comes from my pedal, It sound very dirty not clean like those above bands player. So help me to buy a overdrive pedal which sounds best on Harmonic Minor Scale for shredding