I'm planning my first ever long tour, and am stuck on a couple of decisions about what kit to take. The route is London to Rome following what seems to be the imaginary Eurovelo Route 5 from the 4th July to 4th August. Now the only ever trip I've done has been a 250 mile 3 day trip round the welsh coast which is more than a little bit shorter so could use someone else's expertise here.
I'm on a little bit of a limited shopping budget, but do like to splash out on shiny equipment every so often.
Is it worth getting a gps? As it would make me a lot more confident in the route I'm following, not because I can't read maps but generally forget to and find myself happily cycling far to far along roads I should have turned off miles back

Bike bags - Am planning to fly back as is the cheapest and easiet method I've found, but require the bike to be bagged. The lightest of these I've found is about 2kg nearly as much as the tent itself! Any advice on how to get around having to carry this? Could you try and buy a tarp or something at the destination? Am sure someones already come up with the best answer.
Current kit list:
Tent (3kg)
Sleeping Bag (1kg)
Roll Matt (1kg)
Multifuel stove and cooking utensils (1.5kg)
D-lock and cable (1.5kg)
Repair kit (0.5kg)
Waterproofs
Sandals
1x fleece
1x t-shirt
1x shorts
1x trousers
kindle
More that I'm sure I've forgotten