Use vBulletin 2 instead of vBulletin 3?

[peterska2]

There is a vB 3.x style for vB 2.x - I know coz I made it

Seriously though, unless you have an existing established site running 2.x then you should install the latest version. Not only is support for older versions limited at best, but even the most simple of features which you take forgranted in the new versions are not available without using modifications in older versions. Also, if you did want any customisation to it then you are very unlikely to find anyone who would entertain the project as the code used is now so out of date.