If you like the K100D, I'd say go ahead and get it. The extra resolution and weatherproofing on the K10D are nice. But I think you'll do fine without them. The image stabilization is the really important feature, in my opinion. That will make much more difference in your ability to take good, useable pictures than anything else. Plus, the improvement in image quality you're going to see by just moving up to a digital SLR will amaze you. The K100D will get you started building a system. You can upgrade later, if you find the K100D isn't doing what you need it to. But I gurantee that's going to be a ways down the road. In the meantime, save a couple hundred dollars, and invest in a better lens or lenses instead.