Plastic jackets are awful for most purposes. Useful winter layers are these:
Insulated softshell (I.e Nashbar Derby Jacket, Mavic Vision Winter)
Rain Jersey (I.e Castelli Gabba or Perfetto)
Wind vest
Wool long sleeve jersey
Running tights (over bib shorts)
Cap with ear covers
A wide range of gloves
Wool socks
Lake MXZ boots