Patrick, I think it's a very, very nice camera, really. If you are a beginner with passion and ambitions for the hobby, you couldn't have made a better choice, I think.
So far I only have the two first ZF lenses that were released during the summer 2006, the 1.4/50mm and the 1.4/85mm. As far as I have heard and read the very best ones are the 2/35mm, 2/50mm Macro, and the 2/100mm Macro, while I haven't really heard anything yet about the new 2/28mm, it will be very interesting to read and see some more about that one. Still it would be pretty close to your 2/35mm. Be careful with the 2.8/25, some say it is for some weird reason deliberately optimized for the "cropped" APS-C sensor, not being very well performing in the outer third of the image circle, i.e. with a 24x36mm sensor in your next camera in five years.
Kit Laughlin would be the right person to tell you more about this. He has all of them I think, well that is except the two ones that I have
- which are not considered the best ones as far as I know; yes, they are fast but actually much better stopped down a couple of stops than wide open.
If you are looking for something really wide I would suggest you take a look at the new Nikkor 2.8/14-24mm zoom. It is said to be a completely fantastic performer within the whole zoom range (which is of course also a very short range) and even wide open. It would make a perfect complement to your ZF 35mm which is also said to be very, very good. Also you should not underestimate the value of having an autofocus lens. Inside "Hagia Sophia" / "Ayasofya" I wasn't allowed to use neither flash nor tripod. So I simply put the camera on the floor and let the self-timer shutter-release + autofocus take care of the rest. Very handy in such a situation. But the Nikkor 2.8/14-24mm zoom is a huge lump of glass, 970 g.