I hike into wild country often, and sometimes wild camp in the mountains too. Just remember that if you are camping a tent, sleep mat, sleeping bag, appropriate clothing, map, torch, water, cooking equipment / food on top of cameras, lenses, film, tripod can weigh a bloody tonne. Sounds obvious, but a too-heavy pack is a sure way to kill enjoyment. Might be an idea to do a wee practice-run before setting out somewhere far.
I've been doing this for years, and you need to buy the best, lightest outdoor kit you can afford, and be absolutely ruthless when packing. My packing luxury would be a decent book and / or mp3 player, as you will be hanging about waiting for light to change for hours. Photo equipment-wise, pare back to the essentials. If I'm going on a mountain trip, I don't take my usual range of kit - it's either the Mamiya 7II with one lens, or the Fotoman 617 with one lens, and a lighter tripod than my normal. In the mountains, everything is a trade off.
You need to plan plan plan and keep a keen eye on the forecast for weather windows, or you'll be hanging around in the rain all day. But being up high when the light is good and low at the beginning / end of the day is fabulous. In the UK you'll have to work for it though...
This is by far the most accurate weather forecast for UK mountains: http://www.mwis.org.uk.
This tool might help you plan locations / angle of sunlight: http://photoephemeris.com
and here's the OS 1:50 000 maps online:http://www.walkhighlands.co.uk/maps/.
You might also enjoy the APUG 'Hiking and Trekking Group:http://www.apug.org/forums/groups/hiking-trekking.html
Feel free to PM me.