You can use TOPSwitch from Power Integrations company of USA. These are very reliable. They have been tested by me. Go over to:http://www.powerint.com
There you will find the datasheet, application notes, design ideas and design references needed to build a complete power supply incorporating these TOP Switches.
An alternative to TOPSwitch is the LNK Switch or TNY switch, these also from Power Integrations or the VIPER series from ST Microelectronics. For offline purposes, these are cost effective, efficient and reliable. I am using the TOPSwitch and LNKSwitch for my personal use, while I have heard that the VIPER series and TNY switches also perform great.