Unfortunately I have never seen a list of OBJ values for individual objects.
But the best ways for getting perks quick are flying a reasonably high OBJ bomber and attack towns and, if you got some experience), Task Groups. Because you are looking for targets with a high number of objects being destroyed in a single drop.
Sinking CV's (and CA's) is particular effective way of generating high perks per hour (many perks, short trip) if you got some experience. Blasting town centers is much easier, but takes a bit more time.
Flying for a substantially outnumbered side will also substantially increase your perk gain, A high ENY modifier (can be checked on clipboard inhnagar) does also modify perk gain from bombing objects.