Yeah, exotic plecos are hard to find. I've been searching all over for a zebra, but even the one place that is usually great with their pleco selection (mangos, gold nugget, vampire, etc) don't get 'em in. I would ask at every store you enter what their special order policy is. Sometimes if you make a small down payment, a shop might hit their wholesaler up for the fish. Sometimes shops won't get exotic fish because they are so expensive and very hard to off-load.
SAE should be easier to find. Sometimes they do get mixed in with orders of Flying Foxes or CAEs. Learn the identifications and then truely scrutinize the fish. You should be able to find at least one or two around.
~~Colesea