Choosing between choline types for methylation support?

To the best of my knowledge the three most commonly available choline supplements are...

Choline bitartrate
CDP choline (citicoline)
Alpha GPC​

CDP choline and Alpha GPC are heavily recommended commonly for their neurological benefits as they supposedly more effectively cross the blood brain barrier, which I can appreciate. For general methylation support I have to wonder if it makes sense to spend 10x the money per dose.

Any thoughts or insights on the different choline forms in this particular context?

 

Here's an earlier discussion. http://forums.phoenixrising.me/index.php?threads/favorite-choline.35930/

 

Yea saw that thread, but it didn't really clarify specific intent of the different forms.