TrueCrypt, RIPEMD-160 vs SHA-512 vs Whirlpool

Both SHA-512 and Whirlpool are 512 bit hashes, while RIPEMD-160 is 160 bits. TrueCrypt uses these hashes with PBKDF2 to derive keys. When creating file volumes, Truecrypt uses 1,000 rounds for both SHA-512 and Whirlpool, but 2,000 rounds for RIPEMD-160. I have some software called TCHead that decrypts TrueCrypt headers. It's very simple and straight-forward and demonstrates how and where these hashes are used.

To answer your question, in my opinion, either SHA-512 or Whirlpool would be fine. I would use either and not worry about that too much. Hope this helps.