If you are buying Vega you mine as well just save up and skip the 580 and put that money towards a better Vega GPU.
As for Ryzen, I'd get no less than a 1600 since you are doing some modeling work.
Death is just another path, one that we all must take.
The grey rain-curtain of this world rolls back,
And all turns to silver glass, and then you see it...
White shores, and beyond,
A far green country under a swift sunrise.