You could use an old emulsion bucket or similar cleaned out and holes cut in the sides for the plants, drill small holes in the base for drainage, you should be able to cram in about 10 plants in a large bucket, 5 on top and 5 round the sides, treat it like a hanging basket, and don???t worry about the runners, you will recognize them easily enough as they are quick growing long stemmed shoots which produce mini strawberry plants at intervals along it???s length. Old plants I sometimes allow to produce runners when they come to the end of their productive life, peg these shoots into a pot of compost and they will root readily, make sure there are plenty of roots before cutting them off the parent plant, with luck you will have a new strawberry plant next year and more to the
point, more strawberries!.