This really depends on what you're going to be finishing it with. If you're going to be using a wood paint or a wood oil, you're better off using Barrettine Premier Universal Preserver or Sadolin Quick Drying Wood Preserver which are compatible with most types of top coats.
If you want an all-in-one product which colours, seals and protects, then products such as Barrettine Premier Wood Preserver, Ronseal Total Wood Preservative or Cuprinol Ultimate Garden Wood Preserver will do all of the above. Alternatively, see our wood preservative treatments page for more information.
Disclaimer: Whilst every attempt has been made to provide product information that is as accurate as possible, it's important to clarify that trees and the wood that they produce can be affected by many factors. For example, the same species of tree grown in the same wood, even in close proximity, will be affected by age along with the amount of sunlight and water they receive. Other naturally occurring biological and environmental factors will also influence the density and grain of the wood as well as the moisture and oil content of the timber. No two trees are the same, meaning each piece of wood has the potential to look and react differently to the same wood finish. For example, product adhesion, colour variations, absorption rates and sheen levels. It is for this reason that we always strongly recommend carrying out test areas before starting any project