ORTF on a normal stereo bar will be your best bet (a stereo bar can be had cheap at any music store). you dont want to set up the mics on a tabletop however - you will get wierd early reflections off the table surface. the mics should be around 6 feet up in the air, and if possible, around 6-8 feet out from the source (if acoustic music), or 10-12 feet out in front of an amplified group.