Congratulations
Not so keen on Alyssa (or any "issa" names - they were too ubiquitous where I grew up in the 80s).
Alta I like.
Other names I like (this week) that might do it for you...
Arden
Malin (I had a thread on it and it was almost universally disliked, but at least it is not too popular!!)
And I still love Hero (but it is shocking with our last name), so you should of course help yourself!