Stainless Steel Electric Boiler. These are the best! They have either a one or two 3kw element and come complete with lid , tap and hop strainer. Usually in stock . Requires a bit of wiring, the manufacturer suggests you use an electrician to wire up the thermostat. Comes with a simple wiring diagram, it's like wiring a plug.
We've been using one of these and the insulated mash tun and found it's much easier than messing about with bags.Hop strainer included
You'll need the 75 to make 50 litres of beer! It's a good size and heats up fast with the two elements