Your bike looks great!

I just built up (well my mechanic built it up) a bike for commuting in a similar way with parts I mostly cobbled together off ebay and craigslist (still in the box Ultegra 9-sp shifters--yea!). I wanted a ton-o-gears so went with the Deore LX RD and mtn cassette as well. For kicks I went with a low normal RD, which means it shifts to bigger cogs easier (I live on a hill), but is backwards of my regular bike.