According to the specs on the following page, your BenQ monitor only accepts VGA or DVI: http://www.newegg.com/Product/Product.aspx?Item=N82E16824014240
You can use either but DVI is preferred since VGA is analog and shows some signal degradation at 1080p. You can find a single link DVI-D (male-to-male) at pretty much any store that sells electronics. I don't know about the UK but in the USA any K-Mart or Walmart or BestBuy, Radioshack, etc. will carry DVI cables for sale.
Someone else may have a better idea on your wireless adapter needs since my experience with them is a bit outdated. I use a wired connection, but in the past I've used a couple different USB wireless adapters and both worked great for games like WoW.