If
Porsche (the car) did not exist, I'd be all for the Porscha spelling. But as it is, it's way too close, so I prefer
Portia. Porscha also loses the Shakespearean vibe, so that's another reason to prefer
Portia.
Portia DawnPortia ElainePortia GwendolinePortia IngridPortia EvePortia HannelorePortia IseultPortia GenevievePortia AnnegretPortia MelisandePortia CressidaPortia Luisette
Portia IgrainePortia OpheliaPortia Marigold