May I suggest that a very cheap upgrade would be a tripod? You may be surprised by how sharp your lenses actually are, once you hold them steady! Image stabilisation is a good idea of course. If your interests are more towards action shots, pushing up the ISO will also be a good move. Of course you'll get more noise but the underlying image will be sharper, provided you bias your metering towards faster shutter speeds. Finally, I wouldn't worry about the self extending zoom, even very expensive ones seem to do this. I hope this helps.
