well had the same problem as You and also in 2550

I was afraid of sustainer sounding thin as
neck pickup so after some research I picked Dimarzio Fast Track, but I didn't check this, because I bought new guitar instead

)
You should precise what You don't like about stock single coil and what do You want from the new one.
Do You want sth with no hum, or just different eq or want hi-output mini hum?
