Upgrading to VPS or Dedicated

I am currently hosting a website that is starting to push the monthly traffic limits under the hosting account. So I am looking to upgrade to a VPS. Should I start with a high end VPS or go straight for a server. I think within 9 months I would need a dedicated server. My current host Server Intellect provides both types of servers. I guess my question is, how hard is to migrate from one server to another because I know I will have to eventually. I know DNS takes a few hours, but what else should I look for before I start to move? If it is easy I think I will go with the VPS first and save some money, but if is hard I will go to the dedicated server. Any thoughts or suggestions from anyone who has migrated servers before would be great, thanks.

A webhost is only as good as the technicians and their ability to reply quickly and accurately. On a dedicated host, you set up the server.. at the most basic level, you get remote access to a box and you have to set it all up.

There are two types of virtual hosting have a read here and it depends on what your host is offering and what you need as to whether it will suit you.