I'm not sure what the price difference would be between the two lens and other package deals - but I think you'd find the 55-250mm too slow for the kind of photography you might want to be doing with it. That being said, it's a lot of fun to play with.

The image stabiliser would be good, though.

Give it a bit of a test for motion photography if you can.. but if it doesn't cost that much of a diff ($200-$300 diff) then get it anyway :)