Here's what I use daily for a commute about the same length:
Convertible Waterproof Pannier/Backpack | Banjo Brothers

It's got plenty of space and you can buckly some things to the top as long as it's not raining. Very spacious.

This is a nice idea. In my case I would also need the reusable K-cups that let me use the grinds in the machine. Having said that, I also have not utilized it in over a year when I used to buy K-cups at Starbucks. Prolly cheaper to order them from Amazon. I'm not a big K-cup fan. If I were to get into a machine like that, I think I'd get a Nespresso.

[MENTION=25132]ptempel[/MENTION], forget the k cup machine. Ain't no coffee gonna make that machine's output any good. There are many other convenient ways of brewing coffee. I use a stainless steel French press carafe.

Yeah... I won't likely ride home for lunch. It would be a great lunch workout, but no. I'll either pack a lunch or eat near my office (which is what I usually do). There are several healthy options within .5 miles, including a grocery store.

I went to REI last night and stocked up. I got all the safety stuff I needed, spares, etc. I got a rack and trunk bag as well as the Ortleib back rollers. It's a little sloppier than I'd prefer (one big bag), but it'll work and it's waterproof. Which is good. Now if it can warm back up a bit, I'll get going. I'm in Florida and so we only have like 2 more days of cold... so I didn't want to run out and buy cold weather gear just for a couple of days and I'm loosing weight right now, so by next season I'll be in all new sizes. It should be back to shorts weather by Monday.

[MENTION=456888]tlester[/MENTION], when you say season, you mean September through May or something like that? I hear you Floridians ride a different nine months of the year than the rest of us do. We generally skip winter, and you skip summer. Is that right?

Haha! Pretty much! I plan on riding all year round, but I'm prepared to sweat. It's also not so bad for me right now. This time last year I was 252 lbs. I'm not 195 lbs. By the time it gets really hot at the rate I'm going, I'll be 160 lbs. So, even though it's hot... I've been built like a polar bear for the last 20 years. It's going to feel great to me!

Take a look at sierratradingpost.com

They currently have Ortlieb back rollers on sale. They also have a Racktime back rack (made by Tubus I believe) on sale. I own both and both are excellent.

Also...I don't know where you live but you may want to carry a rain jacket as a just in case item.

I live in Florida and the rain season is upon us (now until October'ish). Summer it rains almost every afternoon. Usually short... but rains nonetheless. I'll get a rain jacket of some sort... as light as I can find. Don't know what to do about my lower half... other than just live with it. Suggestions? Keep in mind, it'll be like 98 degrees!

Fenders to keep the road grime off, and cycling shorts that dry quickly from sweat or rain.

Fenders are on their way... I had to order them.

don't rush mounting those. every set (& bike) is a different tweaking situation

Sorry, I didn't read your entry that you've already purchased much of what you need. I've been to Florida many times so I'm familiar with the daily downpour.

Suggestion regarding the rain jacket...Cheap jackets will cause you to sweat so much you'll be just as wet as if you didn't use it. Speak to some other local riders and see what they use. Check REI and the REI website. You can often find a Showers Pass jacket at a deep discount. (Check the REI Garage site too) You may still sweat, but they have lots of vents so they work very well. A bit pricy but in the heat and rain, very much worth it.

Second suggestion...Don't ride between 1:00 and 3:00 pm when it usually rains.

No doubt!