Brake

Most here will be familiar with this gear, but for what it's worth, Shimano say 105 'makes “pro-level" technology more accessible to part time racers and fitness enthusiasts. The Shimano 105 concept of "Smooth, Round and Natural" is consistently demonstrated in every component, giving its user a sense of satisfaction, pleasure and fulfilment.'

Shimano 105 (5600) 10s STIs £50
These are in very good condition, with some cosmetic scratches. However, having had low mileage, they still function superbly.

Shimano 105 (5600) 10s Rear Mech £20

I've got a Focus light touring bike that i use for commuting. It has Shimano 105 levers and Tektro mini-V brakes. However, the front brake squealed horribly and eventually i gave up adjusting it and bought a long drop (although i had to file out a couple of mm to drop it lower) road calliper.