Thank you for the feedback Force Flow, the feedback and link are both very helpful.
With that said, our CMS is built and it's very custom. Switching over right now just to implement a blog is not going to be the cheapest option. Our website has two user types that have unique qualities. In addition, our CMS has multiple custom things built in to track certain things, produce reports, etc and while those things are probably possible via wordpress/others, we would have to start over from scratch.
I guess a more direct question I should ask is, could have a custom theme developed for wordpress that I would use for the blog and the user wouldn't even know they are looking at two different systems? Users won't be able to comment on the blog posts, we simply need to be able to create articles/content to help our users and for SEO. I just don't know whether I should go through the trouble of custom building a wordpress theme, or just having my developer build article/blog creation options for me within the CMS we have.
A) is it possible to custom theme wordpress to look so identical to my current website that users can't tell the difference
B) what would the rough cost be to have someone implement question A?