earlier in this thread tim mentioned an A5 mule bridge, with an A4 neck.
i have this in a flying V, and i must say i'm very pleased with that mix. gives an extremely broad tonal range, and a great pallete of sounds clean and dirty
i like the riff raff alot, but in my personal opinion it has quite a strong character which always comes through.. now, that strong character is a great one for sure, but i don't find it quite so versatile.
regarding the neck pickup, i know you dont want to change it right now, but i'm pretty sure you will after you hear the upgraded bridge.