*cough*
Welllll... I'm not admitting anything with regards to tapes that may or may not exist, but I do have some information on this...
Answer: not very many. Since she hasn't been sighted in about a year, I can guilt-Reviewee mention Britney Alexander on this site as one WL who was very happy to allow videotaping of her sessions. I think she took the same attitude to them as bands who allow bootlegging of their concerts - it pushes up demand for the 'real' product (for those who don't know, she has or had a porn career). I don't know if her Reviewiend Sarah Jordan (who had a car accident at the start of the year, but no-one in that camp will say how she is) did as well; I suspect so.
And Tabitha (AKA Cathy Oz) formerly of this site is apprently back in action workwise; she also allowed videotaping, for a (sizeable) extra fee. I only know she's back Reviewom a post on AE Reviewiday morning - it was unclear if that's in Sydney, Brisbane or the Gold Coast (I can't access AE Reviewom home so I can't check the thread).
Finally, Annie at Carina did photos and videos for quite reasonable extra charges (but check that's still the case).
Oh, and in Sydney there's a couple too, but I'm not sure what parlours they're working in (and whether they still do it).
Couple of critical points here:
1. if you (and no Rex, this isn't directed at you, it's a generic "you") tape them and put them on the internet, you will burn in hell
2. if you tape them without their permission and you get caught, you will get a broken nose and end up with police charges
3. if you tape them without permission and DON'T get caught, your next reincarnation will be as a crab in John Howard's pubic hair.