So I've been playing around with a cheap $200 Yamaha Acoustic guitar for a few years now, and while I haven't been playing a lot, I've realized that I want to get something a bit more serious than just the $200 guitar.

I really like finger picking and classical songs, but I also like songs like George Harrison's While my guitar weeps

Should I get an Acoustic or a Classical guitar? Any recommendations other than goign to guitar center and trying them out?

Also a friend of mine got a Flamenco instead of a classical to play his classical songs. What is the difference there other than the fact that the Flamenco has a smaller body?

Last question: Do I need long nails to play classical? everything else I do requires me to have neatly cut nails at all times.
Are classical guitars by Cordoba good? I've played a few made by them and I really liked the 30F (flamenco) they have.

Anything else in the $500-$600 range?
For fooling around on classical I don't use nails much... I can't have my nails too long or they just break when I play bass.

If I was to get serious, though, I would probably grow them out a little more.
Nails for use in classical or flamenco guitar aren't long, they are just of the 'right' length. I play some bass as well as classical and flamenco. And yes, I play slap bass.

Flamenco guitars are sound brighter and very percussive. Action is so low it sometimes buzzes. They're fitted with golpeadors (transparent tap-plates like pick guards) for golpes (fingernail taps). Their bracing tends to be different. On the whole, the contruction is different, despite similarities in appearance.

Of course, all these differences apply only to higher end authentic flamenco guitars. Very often, you'll find cheap 'flamenco' guitars made to classical guitar specifications.