Of the Ernie Ball electric guitar strings, which do you recommend for playing Drop C to standard tuning? If that's possible, is it possible to stretch the tuning range even further, Drop B to standard?
I, personally, wouldn't use the same gauge strings to tune to standard (by which I assume you mean E) and drop C, personally I'm a fan of 9s (slinkies) for E standard and skinny top, heavy bottoms (10-52s) for drop C and possibly a size heavier for Drop B. But then again I quite like the feel of a standard 11 set for C standard.

This is all on a guitar with a 25.5" scale length, i.e. NOT a Gibson/Epiphone style guitar. For the shorter scale length instruments I might go a gauge heavier but I'm not a fan of the shorter scale anyway.
R.I.P. My Signature. Lost to us in the great Signature Massacre of 2014.

Quote by Master Foo
“A man who mistakes secrets for knowledge is like a man who, seeking light, hugs a candle so closely that he smothers it and burns his hand.”

Ive used .10s to tune from Drop C to Standard, but they were a bit flimsy. Skinny top Heavy bottoms wont be bad for tuning like this.
Yeah, i would think Skinny top Heavy bottoms would be the best choice.

He's laughing at YOU.
You better click that bastard.

Ibanez RG370DX
Peavey Valveking 112 (w/ Bad Monkey and GE-7 EQ)
I use 12's. I hate the sound of dropped 10's. Actually, scratch that. I hate 10's.
This space foreclosed, due to the ailing economy.
Something higher than an 11. really. I would use at least a 12.-14.
Yeah, now you're gonna die wearing that stupid little hat. How does it feel?

Help me to live.

I make custom guitar wiring harnesses and I'm pretty damn good at it!
I use D'addario 10's (the purple pack) and they work fine in both drop C and standard (I spend most of my time in drop C).
-Guitar Gear-
1995 American Fender Strat, EMG 85 pup
Randall RH200 Head
Marshall 1960a Cab
Woods Acoustic
-Bass Gear-
Spector Legend 4 bass
Washburn Bantam bass
Hartke HA2500
Fender Bassman 410H
Play what you love, love what you play
I use 11s on my Explorer for drop C and it's in drop C most of the time, sometimes it's in D standard or E standard or even drop D and the 11s work fine for me in all cases, every now and then one of my friends who's really into Metalocalypse will want to hear some Dethklok so I'll tune down to C standard and even then the 11s never let me down.

I'm using DRs right now and they're nice my favorites are Black Diamond (the black plated ones) or Elixirs, both of them sound a little wonky when new but after a day or two they settle and sound really nice for metal.