[byteme]

First lets take into account you have made an real £££$$$£££ investment with the 7D (I own one as well) - but its the lens that makes the real difference so if your budget allows go for L lens to compliment your 7D

Have you looked at the 24x70 L f2.8 - superb optics with fast f2.8 makes for a wonderful 'all rounder' - this one is the lens usually attached to my 7D - OK its not IS but with the variety of settings the 7D gives you moving the ISO or (if you are not worried about DOF) changing the F stop will get you the shutter speed you need.

The maybe consider the 70x200 L f4 - for all the reasons of the one above except its f4 - never proved to be a probem to me.

The 70x300 is a good lens but the sweet spot is sometimes difficult to find - I personally found it a frustrating lens and have since sold it.

I can only suggest you avoid the 55x250 you mention - you say its cheap and thats what you get - its a great starter lens but why clamp that to a 7D - you'll get what you pay for!

If your budget allows then the 'new' 70x300 L is a cracker........... but its similar in price to the 70x200 L2.8 IS so its another mortgage to get one............

Hope this helps............... John