I'm looking for a comprehensive electronic list of words or phrases
("e-lexicon"):

a) drawn from some standard English dictionary (American Heritage is
my personal favorite)

b) where each listing is composed exclusively of iambs (iambic "feet"
are two syllable sequences with soft/hard emphases).

c) up to four iambs in length.

My search thus far has failed to yield any such list or on-line
dictionary with syllabic emphasis search features.

This is not a direct answer but a resource you might find helpful
(Pattern matching software).

Rhymesaurus software allows pattern matching.

If you go to this link and look at the examples of the user interface
for the software, you will see a selection under the "Search/Link
Action" line for "Pattern".

http://proaudiomusic.com/songwriting/rhymesaurus_rhyming_dictionary_software.ht

m
	
Pattern Matching 
The Pattern Matching tool makes it easy to find words based on their
lexical stress patterns and beginning and/or ending sounds. For
example, you could use the Pattern Matching tool to find all two
syllable words beginning with the letter "c" whose lexical stress is
on the final syllable.

proaudiomusic.com/songwriting/rhymesaurus_rhyming_dictionary_software.htm

Google put the last letter "m" of the link I gave you in my comment on
the next line and thus made the link useless.   To go directly to the
web page describing the software, cut and paste the link above into
the address field in your browser and then hit enter.

Dear amalik-ga,

Thanks.  Yes, on initial read of their website, looks like Rhymesaurus
may do the trick for me.  Thanks so much.

drscott-ga