Here are my findings:
TM04 (Calm Mind), TM14 (Blizzard), TM15 (Hyper Beam), TM22 (Solar Beam), TM25 (Thunder), TM34 (Sludge Wave), TM38 (Fire Blast), TM52 (Focus Blast), TM68 (Giga Impact), TM71 (Stone Edge) can be bought in the Pokemon Center, Seafolk Village, Poni Island (the fourth island)...