No. A Canon SD850 camera takes an SD chip, which is not compatible with any of Sony's memory sticks.
Lots of camera enthusiasts in forums online will agree that the Canon SD850/950 IS is the best camera to use in a low-ISO environment.
Current Canon digital cameras with those specifications are the A580 (being offered new for $129-$219); the A590 (being offered new for $148-$299); the SD850 (being offered new for $222-$379). All of those models come complete with battery -- and charger for the SD850's Lithium-Ion -- cables, strap, software, and instruction manuals. There is no reason to pay anything near the high-end prices. If you want a case, that will add to the cost.