I'll Walk the High Road: John o'Groats to Land's End

Now that I've decided to do it there are several yes/no choices that need to be addressed:
No, I will not to get fit in advance but will use the first few weeks in preparation by including light training days - backpack free strolls around interesting towns or short circular local walks or simply shorter hike days, after all, I'm in no great rush - I want to enjoy this. Yes, I'll camp out most nights. This allows more freedom as you don't have to book ahead and if you really do get stuck you can fly-pitch - tread lightly, leave nothing but footprints, take nothing but photographs. The downside, you do have to carry camping gear. No, I will not cook but aim to eat light, mostly a fruit and liquid breakfast, a take-away picnic lunch and splurge on a sit-down dinner - hopefully I'll have earned it. Plus, I'll squeeze in morning coffee and afternoon teas as and where I can, so there is no need to carry cooking gear.
No, I will not have back-up but will be self-sufficient and launder clothes as I go, mostly at campsites and hostels which usually have reasonable facilities.
No, I will not buy OS maps en-route or carry a guide book or pratnav. I'll take A3 size copies of Landranger map sections along my route, annotated with campsites, hostels and food pubs/restaurants beforehand. These lightweight copies can then be discarded or easily posted home leaving my library of OS maps pristine. I will also rely on some route strip-maps such as those edited and designed by Harvey Maps.
Yes, it will be a fair-weather hike with warm sunny days and balmy nights.

Kit list:

• Rucksack
• Tent and repair kit, combination padlock
• Mattress and pillow case
• Sleeping bag
• Walking boots, trainers and sandals
• Socks - three pairs double-skinned cotton, one wool
• Trousers - walking, evening and shorts
• Boxers - three silk
• Vests - two cotton
• Shirts - long sleeve, two short sleeve and tee-shirt
• Fleece - jacket, pullover and hat
• Mackintosh (just in case)
• Compass and whistle
• Map photocopies of route - annotated with campsites, hostels, pubs and restaurants
• Map carrying case and waterproof document case
• Camera and waterproof case, mini-tripod
• SD cards, USB card reader
• Torch, rechargeable AA batteries and charger
• ATM card, cash, credit card, YHA card
• Money belt, waterproof wallet
• Travel alarm clock
• Reading glasses and case, spares
• Diary and pen
• JOGLE verification form
  
• Candle and lighter
• First-aid kit - water purification tablets, plasters, blister plasters, antiseptic wipes, Vaseline, thermometer, scissors, sterile water, antihistamines, strong pain killers, super glue
• Sewing kit
• Knee support
• Shower bag - soap, shampoo, razor and spare blades, travel towel
• Dental - telescope toothbrush and paste, dental tape, mouthwash
• Chord washing line
• Plastic cup, hand-held immersion heater, tea bags and coffee granules
• Plastic plate and knife
• Water bottles
• Plastic wine glass
• Penknife with corkscrew (for taking stones out of horses hooves)
• Sense of humour

Budget guesstimates:
Accommodation (campsites, hostels, B&Bs or pubs) £10/night
Food and drink £20/day
Internet and laundry £ 3/day
Total budget £33/day
So, say 100 days walking, trip total: £3,300 or £1,000/month