I would have bought a dual voltage outlet strip, which is readily available in the US, but not here. All of my external hard drives are dual voltage, but unless I buy adapter plugs (which really aren't a good idea) I am snookered. These outlet strips accept almost any plug, so plug in the dual voltage gear, plug into the UK mains, and you are good to go.
Would also have bought the step-down transformers in the US because they are MUCH cheaper. We loaded a 40-foot container, so shipping a little of this and a little of that was not an issue. Aside from that, at least a gallon of white vinegar, household ammonia (for cleaning), a HUGE box of baking soda (also good for cleaning) buttermilk powder (for baking) and at least a year's supply of paper towels (cheaper and better).