Honestly, until you get a much better amp, forget about pickup changes, through a Marshall MG CD10 you'll unlikely to hear enough of a difference to justify getting new pickups, that amp could make my guitars sound horrible, and mind you my Brian Moore Guitars I2000 series listed in my sig is pretty much top shelf as far as South Korean production line guitars go (I have played US made Jackson Soloists and even those didn't play any better than my BMG) and my Ibanez 7 string has some crazy fucking sustain and body resonance, a sign of a high quality instrument.
Just work on improving your chops for now, be it alternate picking, legato, vibrato, bending etc etc and save that money you planned to put towards new pickups and put it towards a new amp instead and you'll thank me later down the track, seriously.