Purchased and installed (2) Corsair 140mm quiet fans and a hand/off/auto (HOA) switch. I removed the existing fan and installed the switch on the 12volt supply. Also I wired in the existing thermal switch to the "auto" side of the switch and a direct wire for the "hand" side of the switch.
The fans are much quieter than the existing and move more air. I haven't had time to check the cool down timeframe but the freezer was noticeably cold in less than 30 minutes. I will post a more thorough follow up when I get a chance to test it.