I have an SX Strat copy that I have been working on...new tuners, nut, electronics, pickguard, etc. It's turned out to be a decent sounding guitar. I just wonder...what's the best way to improve sustain, especially on the higher notes? Would a new trem block or bridge improve things? If so, what kind should I try? Brass? Steel? Preferably not too expensive; I only have about $225 invested in this thing.