If you're doing Hapkido, you don't need Aikido. From what I can glimpse of Hapkido, it is just not as graceful as Aikido. Depending on the style of course. Hapkido is basically Aikido minus the kicks. I think you will just get confused.
Aikido without the kicks and WITH a lot of very sharp techniques and a LOT of serious nerve pain. I don't know how the hapkido guys take the applications I've seen.