I am looking to buy a digital SLR for my 13 y.o. daughter who is becoming interested in photography and already quite proficient with photoshop etc with her old digital snapper. Looking for best combination of features / settings / adjustments while retaining ease of use. Also good quality while not being too expensive. Facility for changing lenses, adding external flashes, fitting filters would be good. What best fits the bill? Any strongly recommended models for this situation?