For HP in Pokémon Platinum, the two Tubers on Route 203 give 3 HP EVs (Azumarril) and 3-6 HP EVs (three Shellos/Gastrodon) respectively. One of them is named Tuber Jared, but I cannot remember the name of the other Tuber. They're right next to a healing location (the booked hotel) and they're right next to each other, making HP training pretty easy.
Battle Hall: Garchomp (49), Leafeon (37)
FC: 2750 8747 1987
White FC: 1420 6672 5883