Use all the “Page Must Have Footprints” from your PDFs to pull massive lists per engine.
You don't even need the Business package, use Pro and throw in some site: tld operators or stop words into your queries if there are more than 100k results for a single query.
Comments
Practical recommendation for you
To cover all seven SERnuke packages at the lowest total cost:
PublicWWW Business – $199/mo
Optionally add Ful.io Individual or Professional – $149–249/mo
Only move up to Wappalyzer or BuiltWith if: