A rack can be fitted with 'P' clips, as long as you keep it light.
As well as the panniers, a saddle bag is a good option, you will need the space if you are camping/cooking
In addition; fit a bar bag, this is where you valuables go and also the map the you are using on the top (GPS to see where you are, map to see where you are going)
I would not even consider a rucksack for touring (What is OK for a 10 mile ride is not OK for back to back all day rides)
Rather than getting a full tourer, a decent non-sus old school mountain bike can be converted into a tourer fairly easily, the gearing is correct, you may just need to change the tyres and fit a rack and mudguards
As well as the panniers, a saddle bag is a good option, you will need the space if you are camping/cooking
In addition; fit a bar bag, this is where you valuables go and also the map the you are using on the top (GPS to see where you are, map to see where you are going)
I would not even consider a rucksack for touring (What is OK for a 10 mile ride is not OK for back to back all day rides)
Rather than getting a full tourer, a decent non-sus old school mountain bike can be converted into a tourer fairly easily, the gearing is correct, you may just need to change the tyres and fit a rack and mudguards