About British passport holders

We are traveling as 4 couples (8 adults) on Nov 4th 2017. We all have more than 6 months after the travel date and 2 blank pages. Can i make an appointment and bring all 8 passport with me on my own and if so how long before we travel can i obtain the Visas ? I assume the cost of a 2 year is £151 and if so can i pay to have all the passports returned to each of the 4 couples address by registered post of if not to just one and again do i have to collect in person