Quantum memories are an integral component of quantum repeaters-devices that will allow the extension of quantum key distribution to communication ranges beyond that permissible by passive transmission. A quantum memory for this application needs to be highly efficient and have coherence times approaching a millisecond. Here we report on work towards this goal, with the development of a Rb-87 magneto-optical trap with a peak optical depth of 1000 for the D2 F = 2 -> F = 3 transition using spatial and temporal dark spots. With this purpose-built cold atomic ensemble we implemented the gradient echo memory ( GEM) scheme on the D1 line. Our data shows a memory efficiency of 80 +/- 2% and coherence times up to 195 mu s, which is a factor of four greater than previous GEM experiments implemented in warm vapour cells.