Found this guide on YouTube that takes you from A -B when installing Search Server 2008 Express for  an existing WSS 3.0 app. :D

Link to guide on YouTube (it’s in German): Search Server Installation on YouTube

After installing the Search Server I needed to add a Shared Service Provider in the Central Administration Site and create a new Web Application for this purpose.

After this was done I could access the Search Administration Site and Config my Content Sources to be crawled.

Then create the  Search Center: Site Actions -> Create -> Sites & Workspaces -> Select Template -> Enterprise -> Search Center Template -> Create

Then you should be good to go!

I don’t think this guide is the correct way but it kinda worked :D Im going to install it a couple of times to get the steps down and catch up on the Best Practice for this kinda installation and configuration.