Here's the 411 for ya from a Horizon mechanic...hope this eliminates the confusion and helps the original topic to be answered.
-NO more Metros...since early 1998, PDX-PSC is served with DHC-8 100's or the Q200's. PDX-SEA is the F28 4000 or either verison or the Dashes.
-We've never had Brasillias...must have been a D0328, similar seating config to the EMB120, or the Metro as you say.
-NO DHC-8 300's EVER....only 100 and Q200 models and US launch customer for Q400 model this Fall.
-ALSO NOW, thanks to American Eagle swapping out...we're launch customer for the the CRJ-700 RJ also starting this Fall.
At present we have, 22 F-28 Mk 4000 jets, 12 Dash-8/100's, and 28 Dash-8/Q200s. The F-28 4000's should all be gone and replaced by the DHC-8 Q400's and CRJ 700's by next October.
Boeing in Pdx, who is the Horizon Commander you emailed in Portland? Most of the big brass is in SEA.
Used to fly the Metro, F-27, F-28 Mk 1000, and the D0328.