700lumens? Best bet would be a Quad mag with LuxV's, bin W or better, running at spec or over. It would be a wide flood type beam and not a narrow beam.
There are some crazy 10-20w leds out, but I don't think anyone has built a mag with one and ran it full power yet? They have large dies, so the beam wouldn't be very tight either, but would be tighter than 4-luxV in 20mm reflectors I woudl guess.