I like the idea Baetram, and I'll throw in that
LibUespQuestData is what I've used in the past for my quest-related IDs (and background text) so I know that has questIDs for the vast majority of quests in the game, but if the other lib has the ids (or indices?) in the data as well then that would work too.
The reason I didn't suggest quest ids is that I don't think there's any way to grab them to compare real-time. Even if you knew the id of a desired quest, you couldn't use code to check that it matches the id of the journal quest. There's no GetJournalQuestId(questIndex). The only way to get a quest's id is when it's shared or removed. Not even when it's accepted.
There's still use for the two mentioned libs to just search the .lua file for a quest name and get its associated id for whatever, but it couldn't be compared to a journal quest directly.