i would go with the 75mm-300mm rather than the 55-250mm ..
the 10-20mm is an ok lens but lacks contrast and needs in my opinion quite a bit of raw processing.. if buying this lens you may want to get a polarizer to boost contrast.. i would recommend a polarizer anyway for use for landscapes etc... i use mine lots!
i started with a 24-70 .. well a 24-105 but i lost it while on a cliff..
a 80-200mm
75-300mm
then bought my 17-40mm
and my 100mm macro
i only tend to carry the 24-70mm the 100mm .. 75-300 and the 17-40 around with me that way i always have something to photograph and the right lens for the purpose
never bought a IS lens as i tend to shoot using my tripod...

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