Name

Both names could work in Sweden! I like Amara better than Aria.
Other suggestions: Vanessa, Vendela, Amelia, Olivia, Dahlia, Eira

They both work fine in swedish, but they might often  be pronounced with a harder more rolling R in swedish instead of the soft english R. I like Aria!

I have never heard any of them here in Sweden. 
Tamara is what I think of when I read Amara. 

Aria is (in my ears) not a real name, but if you like music, opera, you can always claim that is the reason for your choice of name 

Both are possible for Swedish people to pronounce, so that is not a problem, but I think more people than me, will first think they are not "proper" names. 

Super cute names, of those two I prefer Aria. They will work just fine in Sweden.
A suggestion could be "Aniara" after a Swedish poem.

Both work ok since they are not swedish(but also not too weird or unknown) and thus not have a swedish pronunciation to be mixed up with.