Multichoice (Dstv) on Intelsat 10 at 68.5E is available on different cardshare servers, and the signal has good coverage over your country.
One of the members here, junaid has started a test server for DialogTV also. You may find the details here: http://www.rdi-board.com/showthread.php?t=52516
Until recently, ST1 at 88E also had the TBL package which was available on cardshare. But this service has been shutdown at the end of last month. The service is still available on 138E which you may be able to catch, though the satellite will be of fairly low on elevation from Sri Lanka.