So do you think I should only offer Morpheus or would the others be fine also ?
First, the law that applies to your activities might depend on things such as in which country you are situated. You might be in Togo for all I know, and I don't know anything about Togo. Maybe that's where my car keys are.
Second, you are not going to get legal advice on a public bulletin board. When I comment here, it is to provide relevant background that might be generally applicable to a variety of issues. On the subject of P2P software, the Grokster case is a recent relevant case, which draws certain distinctions over Napster. Under Napster itself, however, the knowledge, control, and potential liability rested with the folks at Napster who were providing the indexing service. Whether the liability would have even extended to some third-party distributor of Napster software is, under that case, a completely hypothetical and open question.
But, taking for the moment the notion that a software distributor would somehow "fit" into the Napster side of the Grokster/Napster distinction, whether any piece of software fell on one side or the other is obviously going to depend on how that software operates.