It's a great lens for portraits when you nail focus. Very shallow depth of field so you may want to practice with it for a while. The helicoid can be pretty stiff to turn if it's old. I've taken some portraits I've loved with it, but I've messed up more than I've gotten right. The Volna-3 80mm f/2.8 lens also works great for portraits and is easier. It has a nice glow wide open.
A 35mm lens is smaller and easier to use. Sometimes people want less detail in a portrait so the smaller format can be an advantage. It will also have more depth of field, making errors in focus less critical. Plus, you get more tries to take a good picture. This can go a long way. I don't find 85mm a very long focal length, I think it would be fine for including more of the body. 135mm would be more of a problem.
For B&W, if outdoor, I would shoot under the shade of trees (but not deep forest shade) and use a 100 speed film with not too high contrast. Green or yellow filters can help with skin tones. Acros would be a good choice, many others would work too including Kentmere 100. You ideally want some mix of directional and softbox light, a sunny f/11 with clouds only partially blocking the sun can be ideal. If full f/16 sun, go in the shade. If completely overcast, you might look into ways to add a little bit of directional light, but not too much.
For color, don't be afraid to overexpose Portra 160 to 100 or even 50 if necessary. A cross screen filter will lower contrast a little, as will many other kinds of filters.
Sonnar 180mm on a Kiev 6C (cropped to 6x4.5) and Provia 100F, shade under tree lighting
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Volna-3 on a Mamiya 645 with yellow filter and Shanghai GP3, shade under tree again
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Canon FD 135mm f/2.5 on Canon F-1 with Delta 100 (had to shout at this distance, not recommended) overcast conditions
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Canon T90 with Jupiter-9 85mm f/2 on Kodak Ektachrome E100 (sunny conditions but made sure sun was behind her)
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All of these were shot wide open.