Installation/Support

Firstly I appologise for duplicating this post, but I was unsure which forum to put it in.

Hi Guys, this is my first time on these forums but I suspect it will not be my last.

A little background
I am the guild leader of a game called World of Warcraft. Over 2 years ago one of our main members created a website for us using PHP Fusion v6.00.1.06. This website has been succuesfully running for over 2 years now. Recently we have been having performance issues. The member that created the site has now stopped playing the game and is no longer involved. I managed to get in touch with him to see if I could get all of the details off of him so that I could contact the webhost and try to resolve the problem. Unfortunatly it turns out that we have not paid any bills to the webhost for a long time and although our website still seems to be accessible they have deleted our account and have no interest in our business :-(

I have recently secured another webhost with the same people that we use for our teamspeak server and I am now ready to start moving everything over to this new server. Unfortunatly heres where the problems start.

1. I have little experience of doing anything like this. I have been programming in PHP for about 6 months now, but I have no experience of the server side setup etc.
2. We currently have PHPFusion v6.00.1.06 which has known security issues in it.
3. I have no access directly to the old server, but I do have Super admin access to PHP fusion.

I have read a little of the download manual regarding installation and a simple new installation looks pretty straight forward if it does what it says on the tin :-)
I can back the data files up within PHPfusion and then download them to my local PC

Soooo questions questions

Do i initially have to install v6.00.1.06, restore my data files and then go through some complicated upgrade process to get the benefits of new features and added security or can I jump straight in at a specific version ?

Is PHPFusion 7 stable and ready for general use ? and can I install that straight away and restor my old data files straight into that ?

Initially thoughs are my main concerns, installing and seeing my existing data on a new server. I can then look at installing the existing theme, new features and completly shutting down the old site.

Any Help would be very much appreciated :)