As you have probably guessed by now, most of this is a matter of taste. With that in mind, I'll give you mine. Again, your question will probably get as many different anwers as there are members. The reason is because all of the ones you have listed are basically very good mics . . . but very different sounding. Which one I would choose would have more to do with the type of voice and guitar, the kind of sound you're looking to achieve, and the genre of music.
NT2 -- This will probably give you the most sizzle, sparkle, sheen, etc.
Vocals: On about half the vocalists I've used one with, sibilance can be a factor. Sometimes a problem. Matched with the right voice in the right situation, it can be magic.
Acc Guitar: Very good in just about every case. Proximity effect isn't too out-of-control . . . the multiple patterns give you good options . . . and the natural high-end boost (around 12K) can really make the guitar sound lively and sit in a mix very well. Bass rolloff switch is also a big plus.
NTK -- This mic will give you a warm, flattering, cool sound. Certainly not transparent, and therefore not necessarily good for all occasions.
Vocals: Somewhat hyped in the high-mids, can sound "honky" on a nasaly voice. Great sheen, like the NT2, but a different kind of sheen . . . warmer, less accurate. Think "Silk" as opposed to "sizzle."
Acc Guitar: Must be heard to be believed. Very cool-sounding. Hard to describe, but I really like the way it sounds on accoustic. Not bright or jangley like the NT2. Weightier, beefier. Adds a little muscle to the accoustic in a non-muddy way.
Baby Bottle -- The most accurate, honest, least hyped of the bunch. Very flat frequency response, etc. Smooth in the mids; very ribbon-like. Excellent, professional-sounding mic from a great company.
Of the ones mentioned, this will get you a step or two closer to "the big boys" sonically . . . IF you have a great sounding source. It won't hold you back at all, sonically or fidelity-wise, but it won't cover any deficiencies either.
Vocals: Will give you an accurate, honest portrayal of how your voice sounds in the natural world.
Acc Guitar: Ditto. Might get lost in a dense mix unless you boost the highs generously.
AT4040 -- No experience with it, sorry. If it's anything like the other AT mics, though, my guess is that it will have some hype and coloration to it like the Rodes (focused more in the high mids, though). . . also will likely be a versatile mic, good on many different sources.
SP C1 : Great bang-for-buck. Competes and holds it's own with most of the mics you mentioned, yet for less money.
Vocals: This is it's strong suit. It works well with a lot of voices. It's hyped, but not as noticeably as the NT2. Flattering, yet in a more modest way than the NTK. Aggressive in the low-mids; great for male, barritone singers. Still plenty of air, though, for most female voices.
Accoustic Guitar: I don't particularly like it on acc. guitar. Just my open onion.
It's hard to find a good placement for it where everything snaps in to focus. I've heard some recordings that didn't sound too bad, but I still think there is better for this application.
. . . And that's just one guy's spin on them. I'm sure you'll get a lot more!
- Chess