Hi everyone,


I am hoping that someone can provide me with some direction as I keep going around in circles. Here's the situation. I am relatively new to SLR photography and bought a 40D + EFS17-85mm f/4-4.6 kit plus a EF50mm f/1.8. I travel a lot and enjoy the outdoors so majority of my photos are of landscapes, flowers, wildlife and generally anything interesting outdoors.


Now here's the direction I'm hoping to get... should I look at a better quality lense or would I just be wasting my money. Which of these would you suggest, or should I just keep using the EFS17-85 lense I already have? Will there be a noticable improvement in quality? Ideally I would like to travel around with one lense (plus maybe the 50mm).


The three lenses I am looking at are:


EFS 17-55 f/2.8 - I want to upgrade to a full frame in 3-5 years. 17mm makes life a bit wider on the 1.6 body.
EF 24-70 f/2.8L - No IS leads me away from this
EF 24-105 f/4.0L - Seems like a good all round but is 24mm on the 1.6 body suitable for what I want?


Any other suggestions are more than welcome.