Are you looking for studless or a performance winter tire? Blizzaks seem to be the popular choice for Subaru's. If you want more of a performance winter tire (less road noise) then look into the Dunlop Wintersport 3D's or the Dunlop M3's.
Since you seem to be switching set ups between winter/all other seasons, may be a good idea to actually invest money in your winter tire setup. You are only using them a couple months out of the season, so it's not like you are going to need to replace them every year due to tread wear.
2007 WRX TR | Stage 2 | PAR Gearset (Built by AndrewTech)