You'll be in control with either of these cameras. Go with the less expensive body to start with and worry about spending big bucks later if you're still into it.
Your hunch is correct that image quality is not as good with a very long zoom lens. But take that with a grain of salt because if the image quality was so bad then nobody would buy the lens and the company would stop selling them. If you're upgrading from a point and shoot then you will be very pleased with the improvement in image quality, regardless of what lens you use.
Having said that, I do recommend you buy a telephoto zoom (for instance the EF-S 55-250mm f/4-5.6 IS) to augment the kit lens.
