I am looking to buy another lens for my newly aquired 40d. I would love to buy the next step up to the kit lens 17/85 IS usm which would be the 70/300 IS or maybe the 70/200 without IS, but sadly i cant, too expensive at this stage

going to the states in August dont think the missus would be pleased

with MORE camera gear just yet. Any to the point i have seen a few 50mm/1.8 and 1.4 mark one and the new mark two lens on E bay and was wondering would these fit on the canon40d?. i thought i would try one mainly looking for the sharpness i seem to be lacking with the kit lens .
i intend to use it for the nice sunsets i am hoping to see in florida in august.

thanks