All of our luggage will fit our racks so it is up to personal preference which luggage you choose. We sell each piece separately so if you only need one pannier then it isn't a problem. If you are going to buy panniers as well as a top box then please select the "lift off lid" option as the topbox will cover the lids.
All of your locks will use the same key so no need for separate keys for separate pieces. If you think you will be buying a piece at a later date then please send a message with your order and we will send you a spare lock for the next piece. You can then fit this when you choose to buy the next piece.