I have both the Bob Revolution single and the Duallie. LOVE them both. When I had just my son, I used the single as my everyday and jog stroller. When both kids were in two I used the Duallie as my everyday and jog stroller. And now that both kids are older, I use the single for long walking trips to the amusement park.
Like others have mentioned, your newborn is too young to safely support him/herself in a jog stroller. They just aren't made with all the cushion and head support to handle all the bumps during a jog or bumpy terrain walking. I waited until my daughter was 3 months old before putting her directly into the single Revolution in the reclined position for walks and she was probably about 6 months old before we jogged with her in the Duallie. I never used the carseat adapter. I didn't get our single Revolution until my son was a year old. We waited to get our Duallie until my daughter was 5 months old because we were waiting for the Labor Day Sale at REI.com. They mark down the BOB's by 20%.
Just a suggestion: Is there anyone that can watch your baby while you walk? You might have to change your schedule and walk at a different time, but for now, that's probably the safest thing for your newborn. It's just for a few months until he/she can hold their head up and have better control of their body. Once that happens, it's safe for them to be bumped around in the jog stroller. The only other solution would be to buy the carseat adapter and have your baby strapped safely into their carseat while you walk.
Another option would be to put your baby in a ergo, maya wrap, or kelti backpack while you walk. I used to push my son around in the single Revolution and wear my daughter in her Maya Wrap until she was about 6 months old. Most infants love to be close to their Mama and squished inside a carrier or sling...makes them feel like they are back in the womb, especially if they can press their ear up to your chest and hear your heart beat.