That's a very unusual shaped beech but I think it does have great potential. Something very different from the usual upright trees.
Not clear from the photo angle but I assume this is 2 trees rather than a single tree with 2 big roots and 2 trunks dividing before the first bend?
Both planting angles are OK but I think the second - tilted to the right - has just a slight edge. I suspect the profound bends and exposed roots make me think of trees trying to grow away from some thing whereas the first is generally growing upwards showing there's nothing getting in its way and therefore less reason for the trunk bends.
I can't grow beech here so comments about developing the canopy are general in nature only.
It's likely to take you some years to develop a good canopy on that tree. We generally need to allow the upper shoots to grow then chop back to make new buds emerge to develop ramification. Somewhere in the back of my mind there's something about beech growth that makes me think they may have limited growth spurts each year making branch development slow and tedious. Hope some more experienced beech growers will offer more positive info.
Developing a canopy generally means upper main branches growing generally upward and outward and dividing ever smaller to provide enough shoots and foliage to for m the rounded canopy.
Because much of bonsai is seasonal it helps to add a location to your profile. That way, others may be able to tailor advice and timing more to your local climate.