Best way to make a block render an item?

Hello

I'm making a mod which should generate laying items (sticks, and rocks) on the ground.
 

I already created the block and resized the hitbox, but when parenting the model of it to an item, I have two problems:

1. The model is not correctly rotated (which could be solved quite easily) and way to big (a full block, while it should be only half the size)
2. Because the block not being transparently rendered, it displays the rest of the texture black

When making the block transparent (setting the RenderLayer to translucent) it still does't want to display correctly.

After trying the other RenderLayer modes too it still didn't display as I wanted it to.
 

Now the question: Is this the right approach to make such laying items?
If yes, what should I do to make it display correctly? And if not, how should I do it right?
 

Please help me if you know how to solve this.
If you have any questions please ask