You have a 1.3 Vitz, hence 14" shouldn't be a problem. However, the brand of the tyre matters a lot. A soft tyre like eco will provide less grip, more economy and smooth ride on bumpy roads. On the other hand, a hard tyre like sp sport 9000 will provide more grip, less economy.... the height increase will be almost the same for these two tyres assuming that the wall height is the same.