User Management in CodeIgniter 2.1.0 [duplicate]
Tank Auth and IonAuth are both great for all of the above in my opinion. Each has their own pros and cons. Most notably for you will be the documentation. IonAuth is heavily documented, and well commented throughout. Tank Auth is lightly documented, and is very well commented throughout. I personally prefer IonAuth, and have used it in several projects. If you want some additional modifications to make it even easier to work with, then check out this article here.
Thats your choice dude, If you take an ORM approach neither IONAuth nor TANK will suffice.Choose a database structure throughout your project's then decide, If that means a custom Auth lib, then so be it....