How to upgrade to Android 2.2 [Samsung GT i5800]?
You could uninstall Kies and the drivers completely, and then install the UK version of Kies from here.  (Make sure to select the UK as your location during install).  This should allow you to perform the update, although it might not give you the language you want.  This worked for me to get Froyo on my Vibrant before it was released in the US.  Alternatively you could try another European country that has had an official update released.

You could also try flashing the latest European firmware via Odin.  XDA has a guide on this (see the UPGRADING section).  This is risky if you don't follow the instructions closely and will void your warranty just like rooting, but I've used Odin dozens of times on my Vibrant with no issues.