bro akagi07, u got all the lens i have exactly..
personal i think is getting a UWA lens (tokina 11-16mm) that i got today... haha..
keep 15-105 lens. is a very very good lens.. i wun trade it for 17-50mm lens. as i hav 50mm f1.8 lens already.
get the UWA and get mirco attachment, then u...