Make sure you get one which doesn't hum/buzz itself (it's less likely to hum/buzz if it has a higher power rating than you need).
Make sure it gives out the voltage you really want. Many just divide the input voltage in half. So if your mains happens to be 250V you'll get 125V from them. If you really only want 110V then the 15V excess will be a pain. It may make your kit run hotter. It may make the US mains transformers hum/buzz. It may shorten component life.
If you're not electrically 'competent' then get a transformer that's been safely wired up and enclosed by someone who is.
I'm using a couple of 100V to 230V 1kVa step-ups to run my kit in Japan from Airlink Transformers. No buzzing, high reliability and built like a brick outhouse. I'll be buying the Airlink 230V to 100V step downs to run the sprinkling of Jap kit I now have when we get back to blighty in the future.