Mirissa (Matara) is ideal spot too. It has nice beach, lovely scenery, whale watching, etc. Try Madushani Ayurveda Spa for economical resort and good place.
There is a CERAGEM V3 Thermal Healing Center in Kandy district. You may contact them and ask more details. I heard that if you use a few times like 2 or 3, would be ok. But continual use could side effect.