Hopefully I've chosen the right forum here although perhaps a mod could advise if this question could be better answered elsewhere.

I'd like to hear peoples views about film and kit choice for my upcoming uni trip to Donna Nook. We're going to be guided around the area by a member of the wildlife trust and will apparently come within touching distance of seal pups and 50 feet away from mature bulls according to our lecturer.

I'll be using manual focus gear and plan to take my 70-210mm Series 1 Vivitar rather than my 60-300mm Tamron as it is easier to handle and will probably yield better photo's. I guess that a few shorter primes will be useful for landscape shots or for when we can get up close to the wildlife.
My biggest problem is which film I ought to use, would you use slide or negative film? I would imagine that I would require ISO 400 film considering that I'll need a higher shutter speed with a telephoto lens.

Which film would you recommend to me?

Also is a tripod a must? I have a decent one but don't want to be too bogged down when I'm travelling with a large group.

It's been rather a while since I did any proper photography so I'm pretty rusty really, I shall look forward to your replies.