Creating a player raniking system (Bukkit Permissions)

Ive recently started my own server. Previous servers i have played on have used a rank system where as players play over time, they rank up and gain more permissions.
Id like to set it to where as players log more play time they are allowed to locks more chests over time, be able to set more homes and some other rewards.
With so many servers doing this i was hoping to find a template. But no luck there. and theres about 10 other bukkit permission/group plugins. and i doubt they are all compatible.
right now ive gone thru my permissionsbukkit config with notepad++ and set up permissions for admins and moderators. but thats it.

if anyone can help with this id greatly appreciate it.
Even better if you are on steam. my handle is Hadraniel Solus.