We can definitely use filters, we're not the most experienced with film, so keeping the look of the shots constant is very important for us, as for lighting, everything will be shot during the day with the sun directly above. Only a few shots will be in the morning and at night.
I guess a better way of asking the question would most likely be should we use 50D or 100-200T with ND filters?
For the look, we want a good amount of color saturation, but we mainly want to keep the colors pretty realistic. Since we're shooting a lot of wide open shots with mountains and scenery, it's important to get the reds/oranges but keep the beige sand looking real.