Taman Negara / Elephant Sanctuary

Hi everyone
I'm travelling to Kuala Lumpur for 5 days. I'm really keen to visit the Taman Negara National Park and also the Elephant Sanctuary nearby. I've had a look on the web for organised tours and there seems to be a few but I was a little concerned about paying money over the web before I arrive. I would much prefer to pay for a trip on the day I arrive. So...my question is...is anyone aware whether there are lots of companies / people selling these trips in Kuala Lumpur - if so are there any reccomended companies to go with & whereabouts are their offices / sales booths located?!
Any help would be really appreciated

Thanks
James