As a professional pest controller, I aim to equip the home user with products that are either the same as I use or as close as possible within the confines of the UK Control of Pesticides regulations.
For poison, I recommend Racan Force Paste & Grain. This poison has the active ingredient Brodifacoum and is a highly toxic pesticide specifically intended to target larger mammals, such as rats.
Our Racan snap traps and BORA bait boxes are the same ones I use professionally. The boxes are designed for outdoor use and will hold either traps or poison.