1. You do not need an SLI capable board, only a board with two expansion slots. These could be PCI, AGP, or PCI-Express, as long as both can run together.
2. Assuming you actually meant that an SLI board is needed to run two Nvidia cards together to increase performance, you need the same model, which you did not mention.
Therefore, your advice is either (1) incorrect or (2) incomplete.