These miiiiiiiight work for your application. Just make sure and check to see if the fork has a hole drilled for you to place them, and go query Google to see if anyone has ever fit something similar onto a 29" Cruiser.

Edit: I installed the front brake on my Schwinn Sanctuary a year or so ago. It worked fine with plenty of room to spare, and the only reason I took it off was because I decided against commuting on it...only low-speed riding.