I really think that if you a have favorite electronics shop in your area you will be able to find it the there. We bought a couple of them in a local store, custom made by the store's technicians, and they are so powerful we can plug as many devices as we wish to each of them.
Lik-Sang.com have many decent power converters that should work well for you. Take a look here ->
https://www.lik-sang.com/info.php?cat...ducts_id=1597&