Well, they're totally different animals. Provia is a slide film. Portra is color negative. So this brings the question what you're looking for in a film? Color, evidently. I assume you scan and then post process? Does it need to be 400 or is slower also OK?
Certainly, but the differences are more relevant if you print/enlarge optically and much less so when scanning. Digital post processing, after all, is so flexible that you could get whatever look you want from any of these three films. The most important difference will be speed. Having said that, I was printing some Portra 800 negatives recently and I have to say it's a lovely film. Quite likely my favorite from the three Portras. Expensive, though.