Am away to be building a site and i like the way this site works here is this a custom cms or one of the online CMS

This does appear to be a custom CMS, although it does not look to complex. The same thing can be done with Jooma, and it has alot of plug-ins, so you would not need to hire someone or code yourself every time you wanted to ad a new feature. Is this something you are looking into doing? If so, I would recommend that you find a hosting company that has Cpanel with Fantastico installed, that way you can auto install the CMS with little to no work.