you don't need fans as long as you don't have a splash shield. if the bulbs are encased, then fans should be used to remove some heat. you will get a lot more life out of the lamps if you keep them cool.
i would suggest using external timers. not too many that i have seen have internal timers, except for the current sundial.
this fixture has a splash shield and a fan(s) and is not too pricey-
Current USA Nova Extreme T5HO