It all depends on what you want. If you want max quality, you can kick up the bitrate of the wmv file, if you want minimum file size, you can drop the bitrate. You'll probably want to find the midpoint where you're the most comfortable, with high quality and small file size. Keep in mind that by dropping the audio bitrate, you can also drop the filesize. Framerate is another big factor in video files...
If you still can't find the settings you like, you can try other compression methods. I personally like to use DivX or XviD... They both use MPEG-4 (Avi) compression, and can typically store 2 hour movies into 700MB at acceptable quality (Even at really good quality, it'll most likely fit into 2 CDs [1400MB]).