I also agree with the 70-200 f/4L option. Amazing lens. My dad owns this one too. Most of his keeper shots are taken with this lens. It's a joy to use. I highly recommend it over the 55-250.


Concerning the IS version, I'd say wait on that and just get the 70-200 f/4L non-IS for now. Then you can figure out if you really need IS or f/2.8 (the 70-200 f/2.8L non-IS is in the same price range as the 70-200 f/4L IS). If you need one of the two, you can easily sell your 70-200 f/4L non-IS for about what you paid for it.


If you have the money to spend on the 70-200 f/4L IS, I'd rather get the non-IS version along with the Tamron 17-50 f/2.8.


If you don't have the money to spend that much, you'll have to decide between the 17-50 and 70-200. I assume you probably have the 18-55 kit lens? In that case, you may want to get the telephoto first.


Hope this helps.


Derrick





Edit - Though if you have the money to spend on the 70-200 f/4L IS, another good option would be to get that and the 50 f/1.8 for just 100 more. You could also add the 50 f/1.8 to a non-IS 70-200 f/4L purchase like bburns223 suggested.