If it primarily burgers and steaks you want to cook a gas grill, as Al suggested, would do your job nicely. If you can get one with a lid and space for a smoker box, you could do a little smoking too. My uncle picked up a decent gas grill a few years back from homebase for around £100.
try out this site, some decent offer on gas grills available

Some of the more knowledgeable members could tell you which ones would be best to buy
http://www.hotukdeals.com/search?action ... =gas+grill