All of these shops either currently have parts for the Legacy or WRX or have recently had them.

www3.ocn.ne.jp/~showampc
www.osaka-tireland.net
www.uop-net.com
www.mammoth-nagoya.co.jp
www.toplines.co.jp
www.grip-net.com has a set of Legacy GT 17in rims for about $400 US
www.a-parts.co.jp
http://village.infoweb.ne.jp
www.ishiicar.co.jp
www.i-parts4net.com selling a JIC coilover suspension for the GC8 for $350
www.sutenaide.com
www5.ocn.ne.jp/~nangoku7
www.plaza25.mbn.or.jp/~autolet
www.dream-factory.co.jp
www.yatsuzuka.net
www.2u.biglobe.ne.jp/~scompany/outlet
www.k-staff.co.jp
http://upgarage.com
www.upgarage.com
www.j-mti.co.jp
www.craft-wed.co.jp
045-771-1388 selling a ARC air intake box for the GC8
0466-28-5816 selling a set of coilovers for the GC8
046-204-0300 selling a suspension set for a BG5
042-550-9179 selling a JIC coilover set for the BG and BD series cars as well as a NPG and a JIC coilover set for the GC8
www.naisnet.co.jp selling a coilover setup for the GC8 and one for the BG5
www6.odn.ne.jp6./~creation (think that one is right)
www.naproparts.com
www.rd1.co.jp/autolet-k JIC coilovers for the BG5 for $400