If the place doest give any details, also if its not regstered by the Sri Lanka Tourist Board, dont go with it.
Best advise is that you go with a Sri Lanka Tourist Board registered tour operator
The best two camping operators i know of are Kulu Safari and Leopard Safari
I think they charge about 350 Dollars per night per person
But this charge includes Full days jeep safari, good food, drinks and good service at the camps. You will be well looked after.www.kulusafaris.comwww.leopardsafaris.com/home.html
Both are reputed operators who you can trust.
Hope this info is helpful
Also hope you have an awesome trip in Sri Lanka, and do upload your trip report on this site.
Also like to see some photos