Personally I'm not a fan of the small 16G compressor housings the PDX uses, but hell, anything
will do better in the midrange than that AVO420. Note that AVO has upgraded / updated the exhaust housing on the 380 not once, not twice, but THREE times. Be careful when shopping for those.
Of course ATP has a Subaru flange housing for the GT28RS, but I kinda doubt they sell them separately.