It's not necessary to grow your nails longer for these styles. Classical guitarists almost universally now keep the nails just long enough to contact the string as you pluck through.
A combination of flesh and nail produces the best tone.
That's how I keep mine, and I'm a steel-string player. Works well and doesn't interfere with using a pick in any way.
Ima steal TS's thread.
Does growing your nails on the right hand make using a pick awkward?


Ibanez RG2550Z/SRX430
Alesis Core 1

I'm a student. I've got no time or space for an amp!
In my experience Flamenco is more easily played with shorter fingernails than Classical. It does depend on the technique you're using, mainly for picado runs, but I preferred them less than a quarter of a millimeter past the tips of my fingers. For Classical, about 1 mm past fingertips suits me well, and rolling the strings off between nails and fingers produces a phenomenal tone when done right.

And no, I never had trouble with picks. Except that they sound like crap, I wouldn't advice 8-finger tapping though. Stick to a pick for right-handed tapping. It's doable with fingers, but without utmost care you'll ruin the nails.
Wise Man Says: The guitar is obviously female, she's got hips, breasts... and a hole.
UG's Flamenco Club
My degree is in classical guitar. I have my nails a little longer, by the sounds of things than the other posters so far. But yes, a little bit of flesh and mostly nail gets what is considered by most as the most ideal sound. You don't need to have them *that* long.

That said... I beat the crap out of my nails on a regular basis. I have no issues with alternate picking using a pick, but sometimes I'll break a nail tapping.

The worst, though, is that I tend to hold my pick right up close to the tip (I like pick squeals... haha), so whether I'm playing electric or steel string guitar, I have a tendency to grind my nails down as they rub against the strings.

Could I get some more talent in the monitors, please?

I know it sounds crazy, but try to learn to inhale your voice. www.thebelcantotechnique.com

Chris is the king of relating music things to other objects in real life.