See this page with comments about your question.
You have there some schematics on how you can build your own. I went with the schematic posted by me and it works just fine years later. Of course people who sell mods will downplay the easy solution.
Just go with the best PSU you got and best components you find.
As i said sir., not very efficient. I assume one does test the voltage before using this..
I put this here as an option. Sometimes we dont find/have the components we need.