Just for the sake of conversation and decisions with money, you may consider the Tamron 17-50mm f/2.8 (non-VC). It is as sharp as the Canon 17-55mm, but without IS. It is also 1/2 the price. I still use this all the time indoors and I own the Canon 24-70mm f/2.8. I find it focuses quickly and accurately and is sharp. Also the Tamron focuses closer than the Canon but makes a little noise while focusing due to the non-silent drive motor. Probably sounds about like your kit lens. You could probably get that and the flash for the cost of the Canon and be very happy.