Dynamic stability of a tricycle
The bicycle is a deceptively simple machine.  The physics behind bicycles is actually quite complex, with multiple forces interacting to produce  self-stabilizing behaviour (i.e., ghost ride a regular bike then run along and strike it, the bike will deviate from its current trajectory and self right).  For a good rundown of the main physics principles behind this behaviour, see this short "MinutePhysics" video.

The take home is there isn't a single optimal bicycle handling archetype, but rather there are multiple optimal solutions that are "better" at different use cases.  To start to be able to answer which of your designs might be "better" we also need a clear use case and bicycle dynamics we wish to mimic.

To further confuse the matter the reason bicycles are a intuitive to ride as they are (after an initial training/learning phase) is that balance on a bike also co-ops neural pathways in our brain dedicated to walking (i.e., when we walk we step into the direction we are falling and in the same way we turn into a fall on a bike). Coming up with a functional design that is "intuitive" to the end user will be somewhat complicated, as we must also understand how people walk.  

Taken together you may find an empirical approach (i.e., trial and error) may be the most effective. I would suggest creating a modular design that would allow you to easily switch between a single suspension beam  without any "feedback" coupling, or a design with suspension beams.  Ideally, you would also be able to dynamically adjust the level of feedback so you can vary it until it becomes more "natural."  

Finally, you mentioned


  
  when making a turn the behavior will not be exactly the one of a normal bike as you need a stronger push to tilt the front part.
  


In this case you may want to consider a lower trail front end as it is my understanding that having less caster makes it is easier to initiate a lean.  Also a higher bottom bracket height may also assist in this department (think of balancing a broom on you hand, keeping the weight up high makes corrections easier). [NOTE: I am really outside my area of expertise in this last paragraph, if my understanding is wrong please feel free to add a correction in the comments.]