If you're going to do "people photography", I'd suggest investing in some better glass first. Neither your kit or super zoom are really suited for portraiture. I'd recommend looking into the Canon 50mm 1.4, or the Sigma 50 1.4. Yeah, I know, people are going to recommend the Canon 50 1.8 for $100. They'll tell you it's "awesome!", "best lens I've ever owned!", blah, blah, blah. Fact is, most of the people telling you this have never owned or used a truly good prime before (it's their first ever), and most of those people end up upgrading to a better 50mm down the road. It has more shortcomings than positives. For flash, I can't give a lot of advice as I'm currently expanding my knowledge in that area. What I will say is the 580ex can be used as a master in a multi flash set up, the 430ex can't, but can be used as slave units. That may matter to you down the road.