You may also want to consider hills in your decision. From everything I hear, the Bakfiets is very much a dutch bike, with gearing to match, while the big dummy has more standard MTB gearing. I've been looking at the same thing as my girl has outgrown her front mounted seat and I've been looking at a cargo solution. We're going with a Big dummy because of snow, hills, the ability to put studded tires on (I'm not sure if they make studs for the 20" front wheel on the bakfiets.)
If you just have the one child, you may want to look at something like the bobike mini or ibert as a front seat and going to a cargo bike later since the front seat doesn't interfere with any rack/pannier setup that you've got. The 10mph hug is great fun and I felt much more secure in having her between my arms when she was very small. Totcycle has pretty good writeups on all the options. One issue with the front seats is they're not as good for naps as other options. Long rides are very soporific.
All that being said, the peapod or other bike seats aren't really suitable till your kid can sit up and hold their head up on their own. People have rigged infant car seats in trailers, bakfiets and the Madsen (rear bucket.) It depends on your level of comfort and the laws in your vicinity. In some places it's not legal to have a kid on a bike before 1 year. I personally didn't feel comfortable till she was around a year, but that's largely due to the drivers around here.