I normally carry all that gear on the bike in bags like this , with room in the front panniers for up to 5-6 days food supplies:
Once you have a routine for packing it is a lot easier to put it all together, and if you follow that set routine then it is also much easier to find whatever you need when you are on the road.
All this gear, together with food for up to 6 days, will fit into 4 panniers, a handlebar bag and a rack bag without too much cursing and hair pulling. Careful folding of clothes, the use of stuff sacks to organise and compress some items and judicious organisation of spaces in your bag helps greatly. I like to use a regular pattern of packing which helps to avoid that common touring problem "Oh, it's in the other pannier". When there are four of them it can lead to a lot of frustrated rustling. So, below I give some idea of my system for packing the bags. I like to think of them in terms of packing the different rooms in my 'house'. You may of course use a different system.
Handlebar bag - The Desk
documents
travel & tourist info.
camera
mp3 player
snacks
spare gloves
pen & notebook
sunglasses
Front panniers - The Pantry
Left side - Day meals
lunch & breakfast food
fresh fruit & vegies
snack bars, nuts in pocket
Right side - Evening meals
dinner food
spare ocky straps, plastic bag, blockout, in pocket
Rear panniers - Living quarters
Left side -The Kitchen
cycling clothes
fuel canisters
cooking set
stove
mess kit
cutting board
rain jacket
tool kit & spare tubes in pocket
Right side - The Bedroom
street clothes
sleeping bag
silk inner sheet
head-torch & LED lantern
towel
toiletry bag
spare shoes
pegless clothes line, trowel & toilet paper in pocket
Rack bag - The Shelter
tent
groundsheet
rain fly
Exped Synmat
Helinox camping chair
water bag, map case & sandals strapped under ocky strap