The P2000 is the only one listed on their website that offers 9mm, .357SIG and .40S&W. However I think your neighbor is mistaken about shooting the two larger without a barrel swap. It's possible he's confusing facts and making and an incorrect assertion. THe .357SIG roung is derived from a .40 S&W casewith the end "necked down" to accomodate a .357 (.355 actually) bullet.
The P2000 apears to be in the current line up/offering from H&K according to their website.