Portuguese Sausage in OC
Ebisu Super Market
18930 Brookhurst St, Fountain Valley, CA 92708
Membership but gives 1 day pass for nominal fee
Both have different brands available...
At the meat stand at the weekly Irvine farmers' market (on Bridge & Stanford, Saturdays 0800-1300 rain or shine). I believe it's called "the meat guys". They sell Schreiner's Portuguese sausage from Montrose (up near Glendale -- fantastic German butcher shop) which has received the official stamp of approval from the Hawaiians I know.
Google Ray's Own Brand. They are located in San Louis Obispo but they ship. I have attended several functions at Saucelito Canyon Winery and Ray's Own Brand has come with their portable grill and grilled their linguica for us along with their other sausages and the most incredible grilled sweetbreads you have ever had. I highly recommend this purveyor.