Upgrade from 7.14->8.x and from Ubuntu to Windows 2008R2 Standard

Hallo community,

Currently we are running TeamCity 7.1.4 on a Ubuntu 6.06 LTE server. We want to upgrade to TeamCity 8.x and change to a Windows OS (you may notice that we run a pretty old Ubuntu version).
What is the best way to upgrade, for example:

• should I first make TeamCity 7.1.4 running on Windows and then upgrade to 8.x. ?
• can I directly upgrade both TeamCity and the OS ? Can I simply backup my 7.1.4 teamcity data directory and MySQL (that's what we us) and restore the data in a new TeamCity 8.x installation?

Are there any pitfalls?

Currently I'm aware of the following guides:

• http://confluence.jetbrains.com/display/TCD7/How+To...#HowTo...-copyserver
• http://confluence.jetbrains.com/display/TCD7/How+To...#HowTo...-MoveTeamCityInstallationtoaNewMachine

Thanks in advance for any tips
Frank