I would suggest a ring as well. You could spend the money for an internally threaded barbell. Or on a long metal taper that has a concave back, which will help cover the threads a little as they go through your piercing. But honestly the cost of either would be a good deal more than a simple captive ring. If you're planning on stretching larger, I would wait to start buying more expensive jewelry. And while long metal tapers are always better, this first stretch will probably be the easiest and won't justify spending $10 on a taper.
Buy online if you can. Better prices and better selection. This is where I plug my favorite jewelry store. They'll ship to the UK.
http://bodyartforms.com/
I was two sharks and a monkey.