Emily and Amelia are quite similar. Personally, I wouldn't, but I wouldn't think it was dreadful that two sisters were called Amelia and Emily. They are both nice names.

I do prefer Sophia to Sophie.

Other normal names with L and M, ending with A or E (some are nicer than others, IMO):

Ellie
Ella
Millie
Cecilia
Michelle (many names end with "elle" if you like that sound)
Eliana
Marlene
Maxine
Amanda
Caroline
Camille
Priscilla
Laura
Maura