Both databases have now been combined into one. Buy either one of them and you can have both. Synonyms and antonyms are in separate fields of each of the 144,294 word entries.
Many more words are added. A lot more words now have synonyms and antonyms listed. Over 110,000 words have synonyms listed while more than 21,000 words have antonyms listed.
Here are the details: http://www.thedataplanet.com/databases/synonyms-database.html
Or here: http://www.thedataplanet.com/databases/antonyms-database.html
Separate pages, but the same database.