Hi! Currently have a 450D twin IS kit.

Wanting to upgrade lens/flash. Specifically I will be shooting nighttime events in conjunction with my DJ business! So from house parties/21sts/sporting functions ect. Lots of low light/indoor/nighttime shooting with DJ lighting ect in the background.

I assume the most important thing is a Speedlite? A new lens would also be nice (been looking at the 17-70?) but the 18-55 does do a decent enough job.

any advice appreciated!