Welcome.
Leave the mechanical fan alone

Mark, the fellow making the replacable thermostat, installed a flex fan on his but I don't remember the end results.
In the past several here had overheating problems, mostly on the 05's, and the ultimate cause was the fan clutch

A user here had his-n-her crd's and his would over heat going up their long steep driveway and hers was fine. After lots of time/money spent trying to resolve the problem another member went to help. They put the two CRD's side by side and started them. Her's sounded like a jet engine and his did not even though it was moving a lot of air
It would take a whale of a electric fan to do the job that would use a ton of amps that your alternator would have to supply. End result would be a wash
Just make sure your thermostat is working properly. Blocking the air flow through the radiator will not help if a failing thermostat is opening too soon.