My camera is a Panasonic HC-V700. It uses SD cards. On my camera a 32 Gb SDHC card will give 14 hours on the lowest definition and 4 hours on the high definition, double this for a 64 Gb card. So you are covered with SD cards. Tapes have a finite time irrespective of definition as they run at constant speed.
Most cameras these days are HD. This is not a problem as most editors will read in HD and output to SD, Blu-Ray and other formats.
What will not last is the battery so you will need to run your camera on the mains adapter.
I am looking to record therapeutic sessions occurring over a 6 hour time span. What types of camcorders should I consider? Should I consider tape or hard drive type memory. Should I consider HD? I'm open to suggestions as to what features I should consider and any commentary would be appreciated to get me started.
Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic