Nigel,
Your profile doesn't state where on the globe you currently live, and your post doesn't
address whether power transformers are needed for temporary, or long term purposes(?).

My experience has taught me that I don't want to travel with transformers.
They're just too heavy. Transformers in the capacity you need will approach
(and usually exceed), the size and weight of a bowling ball...or two.

Also, you will have much better luck getting the exact size/capacity transformers for your needs,
if you rent or buy them in your destination country.

Not to worry. People in countries with 220v-240v line voltages are very experienced with
properly sizing step-down transformers (for home, business, and commercial requirements),
for any 110v-120v equipment application that you may have.