Riflemen are the backbone of any army of the era, and as such should be the most numorous of our impressions. Finnish riflemen are famous for their accuracy and stealth.
The most common weapon was the Mosin-Nagant, chambered in 7.62x54r. There are many models, and most are acceptable. All but the M44 carbine model, and the Chinese T53 are acceptable.
Again, it is up to you, but the preffered Mosin is the Finnish M39. It is heavier than any other bolt gun from the 1930's, and extremely accurate, but a tad on the expensive side as far as Mosins go.
Stone gray M-36 Tunic
Stone gray M-36 Trousers (Not bloused)
M39 Leather Belt - dye it black or very dark brown
Stone Gray M/36 cap with round badge
Ushanka - optional.
Helmet - this is where it gets fun, you can use a lot of different helms from most of Europe. Suggested are the German M16, 18, 35, and 40. M42s were recieved very late in the war, they are acceptable but not as common. Hungarian M/38 helmets are very good as well, alongside the Czech M34 and Italiam M/33.
Finland made some of their own helms, the M40 being domestic. These are great if you can find one!
As a note, Finns loved to put vegatation in their helmets, like pine twigs and grasses.
German and Russian jackboots are okay, as well as civilian boots on a case by case basis. No low boots.
Ammo pouches- German WW1 pouches, M/27 pouches (Be careful, they resemble Kurza pouches from postwar Russia), or a rubberized canvas type which is very rare. Usually Finnish soldiers have one ammo pouch, or none at all, as ammo was commonly carried in the breadbag.
Breadbag- German WW1 breadbag, or the Finnish model.
Canteen- German WW1 type, German WW2 type, or Finnish type (Look up the Finnish M/42 canteen).
Mess tin- WW1 or WW2 German, or the British type. Soviet is okay as well, but lets limit that to one per squad.Rucksack -not required but a good buy for food and other items. The Finnish type will be large and brown. Hiki has a rucksack, which would preferably be darkened.