I don't know how much experience you've had with rubber trans cooling lines, but I've run into 3 different occasions in the past 10yrs: 2 intrepids and a stratus where rubber hoses have leaked. 2 of the three were due to barbed fittings, overtightened gear drive hose clamps shredding the hoses. The third was a factory rubber hose in the middle of two steel lines which became saturated with oil and just sweated ATF. So, yeah rubber hose may work for you, but I don't think the convenience of rubber hose is worth the risks.