Bicycle Mechanics - Brake Options for Commuter build

I'm thinking about my next commuter bike, which will probably be based on a cross frame. I see lots of commuters builds with barcons, but I have 105 STI shifters on my road bike, and I love them.

What are my brake options? I know I can use cantis, but I worry about stopping power (I'm a big guy, and I go up and down some steep hills on the way to work). I might be able to use a front disc (I already have a good rear wheel that I want to transplant, and it is set up for rim brakes)

Any other ideas? Thanks in advance.

How about long reach double pivot sidepulls? V-brakes with Travel Agents are another possibility. Properly set up Cantis can be quite powerful too.

I need to be able to run both winter tires (e.g. Nokian W106s) and full fenders for winter commuting, so I think that any sort of caliper brake is probably out. One of the drawbacks of my current hybrid is that with fenders, there is enough clearance for a 32 mm tire, but not much more.

I have V-brakes on the hybrid: they work, but I'm not thrilled with them. I seem to spend a lot of time adjusting them to get rid of squeals, etc.

I've heard of travel agents, but I'm not really familiar with how they work.

I do see people with a number of people with cantis, so that may be the route I end up going.

I've heard of travel agents, but I'm not really familiar with how they work..
Travel Agents are a double pulley device that changes the cable pull ratio between the brake lever and the brake itself. They allow road brake levers/brifters to work properly with V-brakes and some mechanical disc brakes.

However, there are disc brakes designed for use with regular road levers so you might want to consider these too.

Cantilevers are my favorite caliper brakes. I just built up a Surly Cross Check with inexpensive Shimano cantilever brakes. They're wonderful.