as small or big as you need or can afford.
Well, the "big mouth" isn't the exact term, but if u mean "smile"(the one that looks fake and shows teeth which is just a white blob" than it doesn't matter what kind of gems u used, just as long as he combination turns out rare. If u have no idea what i mean, than u can use "ruby, sapphire, sapphire" or "sapphire, sapphire, sapphire" or "emerald, sapphire, sapphire"
strength
sky pillar for claydol
banyon
70 for the big bottle (liter)
Take it to the one island pokemoncenter and give it to the guy near the big machine he will let you trade with ruby and sapphire and emerald now!
For Sapphire and Emerald, they are not in the cave
may be around 1 inch diameter size. 60 grams
Go to the route east of fortree city and look in the big grass.
You can find it in the city called Mauville City the big purple building.
Give them to Bill's friend in the big Pokemon Centre on One Island!
you can get some in the big department store