Hi there! Based on your need for a voice recorder with long recording time and the ability to hide recordings, I'd recommend either the Olympus VN-541PC or Philips DVT2110. Both of these digital recorders have 8GB of memory, which should provide many hours of recording time. They also have options to assign passwords to file folders, allowing you to keep private recordings secure. The Olympus is more affordable at R1499, but the Philips has a colour display and dual microphones which may be useful. Hopefully one of these suits your needs! Let me know if you have any other questions.
