the best wa to make all these products work together is to have them use the same users table.
The following tutorial gives a way for using your own user table in power messenger:
http://www.webassist.com/tutorials/Using-your-own-users-table-for-PowerMessenger-experimental
this can be used to make power messenger use the power store users table. it could also be used to link the community directory table.
We can help integrate these products together i n a premiere support appointment.