the sizing is standard bmw,
the odd thing is i usually go for a 52 but ended up with a 50, as the 52 felt like i needed more layers, but i do like a fairly snug fit,
stick to the standard fit size you should be ok,
i have dainese stuff which is definitely a size up on what normally fits but still a close fit,
warm enough for winter might get away with a bit of summer riding, definitely waterproof,
Hope this helps,