IMHO Russian vets are a better option, although the pilotka (side cap) is incorrect for a Finnish soldier - and I'm not sure whether ushankas are ok or not. Plus the PPSh-41 wasn't that popular with the Finns due to it's unusual calibre, though they did use it sometimes.
As for Gebirgsjäger, their boots and most of the jackets are incorrect, they seem to have too much equipment (looking at photos of Finnish troops, they rarely have backpacks unless on the march), and German weapons were quite rare in the Finnish army.