I've also got a commute of 17 miles each way.
1) For breakfast I have a big bowl of cornflakes, muesli and a banana, with lots of milk. It's never let me down yet....
2) I alternate between two bikes: Road bike with Continental Ultra Gatorskins, and Cyclocross with Michelin Pilot City - both have been excellent (so far) although the wider Michelins are better on the choppy roads I have to use.
3) I use a cheap backpack. Yes, it gets a bit sweaty but if you can keep the weight down, it's OK. I cheat a bit by driving in on Monday and bring most of the stuff I'll need for the week. I've also got in the habit of emailing files home that I need to work on and leave by laptop at work most nights. That made a big difference.

Good luck with the new job!