Evaporative Water Coolers - Damper and Thermostat

I have a swamp cooler with 5 duct runs. One of the ducts is a 18" run that feeds an open area to the first floor of the house (over the stairs) and the other 4 runs are 6" runs that feed 3 bedrooms upstairs (the master has 2 6" runs.)

With this configuration most of the air goes through the 18" run (it is quite a bit shorter as well) leaving the bedrooms without much air. Closing the vent just generates a lot of noise so I purchased a mechanical damper for the duct so I can control it up closer to the cooler.

I currently have a standard rotary control for the cooler with pump only, low fan, high fan, low cool, and high cool.

My question: Is there a digital thermostat I can get that will replace the rotary and also control the damper?

Thanks

Id say for the damper yes but for the blower motor no. Id say change that 18" run .Cut it down in size it can carry about 900to1000 CFM. The 6" runs should have about 100 CFM .
You should balance it out with the ducts.;)

I would like to keep the larger duct as I typically want to use either the large duct or the small ducts, but not both at the same time.

My current thinking is to put in a mechanical damper on the 18" run, replace the existing thermostat with a digital one, and add a standard switch to control the damper.