Hello Simon.
You may have to purchase a router through virgin media, your ISP. You might call them and ask if you have to use one of their routers or not. Ask how much it is as well.
The following may not apply to you:
{Likely you would have to search the internet in your particular region. In addition, you may just want to go into your local computer store, such as best buy, and ask them what the cheapest solution to your needs is. From where I am at, its an average of 60$. If you shop locally, you wont have to wait for it, and you can ask questions. You also don't have to pay a shipping fee.}