I have two and a half packs of Evocore Classic Herringbone Golden Harvest Oak flooring left over from a larger project.  Each pack covers 1.35m2 so there should be enough to cover 3m2.  No underfloor material needed but needs to be a flat solid surface like concrete. Buyer to collect.  Easy to cut and lay as they just click together.  Each board is 300mm L x 75mm W x 5mm H (+1.5mm underlay).