Well, you can create your own Party in NWN 2 with the following Mod:
http://nwvault.ign.com/View.php?view=NWN2Other.Detail&id=118
and use this mod to multi-class your characters and pick prestige-classes:
http://nwvault.ign.com/View.php?view=NWN2UI.Detail&id=86
and then there is a cheat-code to increase the party-limit to 6 or even more characters
And here is a costum party mod for NWN 1:
http://nwvault.ign.com/View.php?view=Scripts.Detail&id=2568
but of course the henchman system in NWN 1 is kind of stupid...
http://nwvault.ign.com/View.php?view=NWN2Other.Detail&id=118
and use this mod to multi-class your characters and pick prestige-classes:
http://nwvault.ign.com/View.php?view=NWN2UI.Detail&id=86
and then there is a cheat-code to increase the party-limit to 6 or even more characters
And here is a costum party mod for NWN 1:
http://nwvault.ign.com/View.php?view=Scripts.Detail&id=2568
but of course the henchman system in NWN 1 is kind of stupid...