The problem: Using older version of components on this project.
How huge of a project: enterprise resource planning (around 3.000 .pas files)
Why isn't it a matter of replacing old for new one: If it was, I would've done it myself. The Project has a custom package, in it there are the components that need replacement on the requirement area, if you simply replace the old for new one, the Custom Project Package will not load.
DevExpress 5.xx (2007) -> DevExpress v53
TMS 5.7 (2010) -> TMS 126.96.36.199
Don't think it will be an easy task, you'll face things like "x was compiled with a different version of y", and possibly "property x not found". So, you need to be a Delphi guru.
Name your price and leave your mail, I'll contact you asap, I'll be checking this post a lot since I'm not quite sure how long will the community allow it to be up.