Bit dangerous using a film camera for the first time on such a trip. You need to be much more discerning with film, you cannot just delete the dud images and you do not know if you stuffed up till the pikkies come back, but don't let this discourage you, I got some great photos on my very first roll of film tested just prior to a walking trip in Tasmania, which also yielded some beauties. This was the start of my rather extreme 35mm SLR passion/obsession. On the plus side, if you get a great shot, it can be enlarged substantially. A 28 f/2.8 is a very usefull lens if you are after brute quality, but a zoom, while not having the resolution, gives the versatility of not having to crawl up or back away from the subject. A 28 to 70 and an 80 - 200 zoom is probably all you need. A small flash is also very usefull for fill in or very low light. Get someone to show you some basics, eg how to load film and rewind properly and metering tricks. If you are in Sydney,I have a Tamron 28-70 SP and 80-210 SP Tamron with Olympus mounts for sale which belong to a friend of mine who has entrusted me to sell these items for him. A small tripod is usefull. Of course, you can take me in the luggage as personal photographer!
