php-gtk2 ready for new project?

Hi there, I would just like some thoughts on this from those that have been using php-gtk for longer than I have (1 week). I have to develop a rather complex elaborate modular application for a specific company (hoping to use it for more) and as I'm most comfortable with PHP from relatively advanced web development and server cli scripting, I would really like to do this project in php-gtk. However, since we're starting off now from scratch, I would like to leave all kinds of migration and upgrading and re-development out of the equation. At least as much as possible, hence I would really like to rather use GTK2 than GTK1 (I would also like some of the php-gtk2 features which I am missing at the moment). Our projected development time is around the figure of 8 months. Would it be fine if we started development with gtk2? I do know it is still unstable and undocumented and such, but it seems to be a better idea than sticking to GTK1 currently? Anyone that have any thoughts on this at all? Thank you very much