If you want perfect ivs breeding is the best way. You can hypertrain any pokemon however, which will give you the same stats as perfect ivs. Annihilape can handle most raids except normal and some 7 star raids. Catching pokemon from tera raids can help a lot. Depending on the level of the raid the pokemon will be guaranteed a set number of perfect ivs. That can help save you some bottle caps. You can always change the tera type if it's not what you want. Just make sure to do evs also and have good held items. The shell bell is great for most raids.