I've got a couple of Trulink Wireless HDMI kits. They work fine, bit of a faff having to install the drivers initially, but other than that they are ok. Main reason we don't use them too much was you cant have multiple receivers running from one USB dongle, and we had 2 screens in our boardroom. Ended up getting them hardwired into a HDMI splitter box.
They might be out of your budget though, around £150.