I know of no »Merge Paint Tool« in Photoshop.
What functionality are you talking about exactly?
Do you mean the Clone Stampl Tool?
For Photoshop Elements questions please refer to the appropriate Forum.
[Moved to Photoshop Elements Forum]
If you can tell us about the funtionality that you are looking for , then we can guide you the right tool in Photoshop Elements. Currently there is no tool with such name in Photoshop Elements