We have an asymetrical light air sail on Peace IV which we bought from Jeckyls in Britain.  It works fine but I cannot say what the dinensions are because we have never measured it and I doubt that it is anywhere near as big as Chris J says it is.  We have a snuffer sock that also works well.  We attach the tack of the sail to a shackle that joins a pair of lines that we can adjust to move the tack from the port side of the bow to the starboard side.  These lines run through blocks we have tied to the bows and from there to the aft end of the forward mast case where we have some jam cleats.  The sheets for the sail run outside everything to blocks well aft and from there to the usual jib sheet winches.  It is a fun sail in very light airs but I must be reminded to take it down as winds strengthen!