The vast majority of "minor-sounding" tunes in Irish and Scottish music are modal tunes, which means that, provided you choose the appropriate-key harp, there are no accidentals to get your tongue around. You really don't need those Lee Oskar minor-tuned harps at all (though I'm not saying they mayn't be fun...), and, personally, I have no use for Melody Maker tuning either. These harps may well play the tune you want, and be nicely funky, etc., but so will the standard harps, and, unlike the standard harps, they will screw up your ability to play sets of tunes with key-changes (which is restricted enough as it is in Irish with diatonic harps). Stichter Richter, say I - even better, tune up 3-blow on your harps a whole tone, giving you the Paddy Richter tuning which restores the missing 6th note in the bottom octave.