The extra engine and tranny cooling are a must to reduce wear! External Tranny oil coolers are available but the extra radiator capacity and 2nd cooling fan are harder to find aftermarket.
I tow a 2800 to 3000 lbs trailer with my 2000 with the towing option. Like posted before you need to change the Tranny oil and filter at least once a year if not twice if you are towing regularly and or in hot weather.