If you're looking to buy something new, a lot of hybrids might be appropriate. Consider the Trek FX series. The 7.3FX might work for you if you can find one that's the right size. Also, the price point would leave you money to buy fenders and a rear rack (better than a backpack, especially if you're in nice clothes.) For a road/ CX bike, the price range is a bit low, but a Cross Check would serve you well. Of course you'd have to add fenders, lights and a rack after, t the $1,059 price tag would run to $1,200 before tax.
If your mechanically inclined or know of a local bike co-op that can help you assemble a bike, the Velo Orange Polyvaltent Mini Build Kit with additional parts could give you a really nice bike, one that you can ride anywhere an any conditions and that's customized to your specs.