Milotic- Blue pokeblocks that increase beauty. (Can make these
blocks in Lilycove city, one combo to make them is Lum + Oran berries)
Johto Starters - in hoenn safari zone.
Totodile - water area (waterfall place)
Chikorita- Gligar patch grass
Cyndaquil - Houndour patch grass (i think)
Those BP you earn in the matchmaking pop are used to get items in the Battler frontier or you can sell it to ppl (buy the item for them and get profit Ez trade)
Some example of these items are Swift choice band (Scarf) Specal choice band (Specs) and Life ball (Life orb) costing about 9.8k BP if I remember.
Ranked pvp = 4K BP
unranked pvp = 550 and I think it increases if winning streak