It seems I have had a change of luck! Today in the mail I got the following items:
1x replacement Canon EF-S 17-55mm IS
1x replacement Hoya Pro1D CPL
1x Samyang 8mm Fisheye
1x Transcend 16gb SDHC
I also received an email from ebay informing me I have been refunded in full for the Canon 70-300mm L that I was having trouble with!
Even more amazingly the Canon lens is the best copy out of the 5 I have had so far, focus still isn't perfect but it's the best I've tried, it gets it right a lot of the time and when it doesn't, recomposing the shot normally does the trick. At the very least it's better than no lens at all! Hopefully at least one day at Bristol balloon fiesta will result in some sunshine so I can really put the lens through it's paces!
The Samyang 8mm is quite remarkable, it's very sharp at f/5.6 and has excellent edge to edge consistency despite the incredible 180 degree angle of view! It's such a cheap lens in the scheme of things especially considering the ambitious optical design so I am very impressed that the quality control appears to be so good! It's not going to be a lens I can use every day and the novelty would quickly wear off but I get the feeling it will be well suited to taking photos of hot air balloons.
The Transcend is a great memory card and I already have one which has worked flawlessly for the past 8 months, they may be affordable but in my experience they are rock solid unlike Patriot and several other cheaper brands!
I'm still waiting for a spare battery but I will have access to mains electricity so I could probably cope in a worst case scenario, on the whole I am much better equipped for the trip to Bristol.
Now it just remains for either the weather or riots to ruin everything!