Cheers for the responses guys, much appreciated.
Michael - unfortunately I don't think there is a way to change to pounds and ounces in individual items, I have the same problem when looking at other's lists, I can only work in grams! When I need to convert an item, I type into Google 25.5oz to grams for example, it converts it for you.
As for the advice - I don't think we have gatorade in the UK, but I'll take a look around for a lighter bottle. Were you referring to the Source 2l bladder bottle, or the regular buxton water bottle? Also, the buxton is 1L, is that the same for the gatorade?
I was using a raincover because my Atmos has lots of external pockets and I have gear stashed away in those for easy access, but they're not in drybags. However, I have just sold the atmos and I'm looking at getting a new pack with 1 single main compartment (thinking of getting a Granite Gear Vapor Trail before they all disappear). I need a lightly framed pack rather than frameless as I have some existing neck and back issues. Once I have that, I might just use a rubble sack to protect the inside, and keep 1 of the drybags for my down sleeping bag. In the UK it's very wet and rainy a lot of the time so I like to know that my down bag is dry, that's a weight penalty I'm willing to pay.
As mentioned earlier, I'm getting a new rucksack - many of the US brands aren't easily available in the UK, but the vapor trail seems a good bet.
Blacks stuff sack - that's just used for food, never really considered ditching it, but I could just use a plastic (grocery) bag, would be a lot lighter.
Stakes - my tent requires a minimum of 8 stakes, but 10 if you peg out the middle 2. I was carrying 2 spare V stakes because I didn't trust the toothpicks in very soft ground. But I could just ditch 3 of the toothpick pegs and save 6g. Though I have been thinking of just using sticks recently, might experiment with that.
Sleeping bag - I could get something much lighter for Summer use, however, I use this one bag as I don't really have a lot of money to play with at the moment. I would still keep this for October - May time as it's fairly necessary in the UK. But I might think about changing it out for something lighter in the future once I have a bit more cash - I'm a student at the moment.
David - I think I've replied to most of your response above. However, with regards to shelter, I really like the comfort of a fully enclosed tent, especially as conditions in the UK can be pretty unpredictable and very wet at times. However, I have been considering a tarp, but it's not a possibility due to a lack of money at the moment.
But for the future, could I set up a fully enclosed shelter with a large enough tarp? If so, what size would I need? Also, I worry about needing a bivvy bag if I'm using a tarp in very wet conditions as I have a down bag. Would this not remove any weight savings anyway?
Thanks for your help so far, it's given me some food for thought.