StaffListPlus
StaffListPlus make it posseble to create an inventory with player heads in it, you can add them by you own. There are in total 36 slots, need help with slots? Look here. The inventory has the title 'StaffList' in chat color green, this can't be changed. This plugin don't have a config, this is maybe coming soon.
I'll add suggests, place them in the comments below!

Commands

/staff : Opens the inventory
/staff help : See all commands of the StaffList plugin
/staff add <SLOT> <PLAYER> : Add someone to the inventory
/staff remove <SLOT> : Clear a slot

/stafflist : Opens the inventory
/stafflist help : See all commands of the StaffList plugin
/stafflist add <SLOT> <PLAYER> : Add someone to the inventory
/stafflist remove <SLOT> : Clear a slot

Permissions

stafflist.add : stafflist add command
stafflist.remove : stafflist remove command

What to do if you need help?

Post a ticket.
Post a comment.
Send a PM.

TODO List

Slots customised in a config.
Let the remove command work on player names too.
Config reload command.