Bob,
Others may disagree but gags are unnecessary and in untrained hands can be damaging to the fish.
Try and enlist an experienced piker to show you how to safely 'chin' the pike. This method, when used properly, is quicker and far more controlled.
As Tom says check out the PAC website for handling tips.
Your minimum kitbag should include, 15lb monofil or 25lb plus braid, a 2lb tc plus rod, a large unhooking mat, side cutters, long handled forceps or pliers, 28lb plus wire, appropriate crimps, crimping pliers, semi-barbed hooks, Kryston Klinik or similar and a very large landing net.
There are several FM'ers in the Bristol area, why not start a new thread and ask someone to show you the ropes?
Hope that helps mate.