It depends on your set. I have an omni directional condenser mike on a tie-clip. It cost about £20.00 and was designed for a dictation machine. It works on all my guitars, citterns, drums, whistles. Put through a 7 band EQ pedal you can tweek the sound to suit. The trouble is if you have chanter, drones and regulators, where do you place any kind of contact or "on instrument" sensor be it mic, pick-up or transducer? Nick Scott of "Last Night's Fun" uses a simple front angled mic and as far as I can see from the audience, "Chieftan" Paddy Maloney usually does the same. Davey Spillane sometimes seems to use a fairly complex set up to control all three sources independently but I've never got near enough to work it out. All in all I reckon a good quality front mic is your best bet unless you want to spend serious money.