What Motorhome to buy?

Hi everyone, I know this question has propably been asked a lot of times but I really need advice and guidance on what van to buy. I am looking for a 4 berth van with a fixed bed. I have a budget of up to £30,000. I have trawled the internet and visited a few dealers, but they dont seem to have many vans in stock. Any advice is much appreciated. Thanks.