Customer area (individual private areas/pages)

I am working on a new site for someone, and I’ve incorporated a wordpress blog into their site. The majority of the site is written using the CodeIgniter framework, but I’m half tempted to move most of the static pages into WP and have the whole thing running off that.

One of the requirements is to create a customer area, where people can log in and check on progress of work. I could create a new database and users system, but I’m thinking it makes sense to tie it into the WP system, so that they have a single sign on for the entire site.

The question is: is there a plugin that allows private individually accessible user pages to show progress and news updates for the individual user, or am I going to need to hack this feature in myself?