Does anyone have any experience with Marfin Laiki?

They are based in Cyprus but are they reputable as a UK bank - we are thinking of using them for business banking?

Why on earth would you use an offshore bank - where you would have no FSA protection - for business banking?

Are you actually located in Cyprus, or the immediate area? If not, there's no reason to consider them an option, and every reason to consider a UK bank instead.