Clean rhythm and string gauge

Hey y'all, it's been a while!

I like playing clean rhythm. The most dark, bizarro-sounding chords I can find in the chord book (or randomly make up as I go) is what I like to play. Of course, most of the time the setting has to be quite clean.

Right now my guitar is strung with 12 gauge strings, dropped to C#. Ehhhhhhh... I think I need something thinner.

I've been told that 10 gaugers are optimal for metal rhythm in terms of tone. Would that be the same for clean rhythm? That would be cool, because then I could go back and forth between clean and thrashin'. What about 11s? Also, if I go with 10s or 11s should I tune it up closer to standard so that there's more tension? I've found that 12s detuned to C# are still like a friggin' piano if it's set up right.

Also, what kind of pickups are best for clean rhythm? (On a solid body guitar, I mean.) Any recommendations? I really like P-90s, generally speaking, and am fascinated with the idea of humbucker-sized versions, but I do want maximum tone/harmonics/oomph... all things considered.

Don't play an awfull lot of cleans myself but I've had a tonal revelation recently which I first tried out on my 7 string electric. I keep the lower three strings on a guage 10 for meatier rhythm tones with the upper 4 on 9's for lead. I'm doing the same now with my 6 strings too but with the upper 3 strings using the 9's and the lower using the 10's.

11-52's work really well for c tuning in both clean and metal modes I even play them on my standard tuned guitars.