I have the Samyang 85 F1.4. It's phenomenal for portrait. It's sharp at F1.4, great optics, rivals things that cost $600+. It's no 85 F1.2L II, but it's about as good as the $900 Sigma F1.4 version, just lacks autofocus. That's no problem to me though, as with this kind of razor thin depth of field, manual focus is often used anyways (for me).
The 50 F1.4 is an ok lens. It's better for indoor portraits (on a full frame). But the lens is not that great, not super sharp at F1.4, and the build is not fantastic. Not worth $320ish in my opinion. I'd rather just use a Helios 44-2 (58mm F2) manual ($40!), or if you want autofocus, look for a good copy of a Sigma 50 F1.4. I found 50mm on a crop sensor to not be right for my style. I much prefer 35mm and 85mm on a crop for portrait. 35mm indoors. 85mm outdoors.
The Samyang 35mm F1.4 is also a great lens. Also, don't discount going manual/vintage. A super takumar 50 F1.4 for $60~80, and a helios 44-2, 58mm f2 for $45. Great portrait lenses for all purposes, crop and full frame.
Don't forget lighting though, this is where portrait really stands out.
I'd get an off-camera flash, like a Yongnuo 560 III and a wireless trigger. Inexpensive. Set up in a softbox (Newer 60cmx60cm for speed lites, only $30!) and a light stand (impact) for like $25. Good to go.