Nominet don't make the zone files available to joe public, if they did, everyone would have 100% accurate lists with every name on them.
To setup all you need is DAC access, write a bit of code to pull in your word list, stick a .co.uk (or other desired .uk extension) on the end of the word, open a stream to the DAC, stuff in your list record by record and record the results back to your list, simple really.
If you use a database for your list you can then run simple queries each day to get your drop list.
Take it a step further and you can re-use some of the DAC code along with an EPP or PGP registration engine and catch your own domains.
Naturally, you'll need to write your own code in your preferred language to make it happen, but everything you need to know about the DAC, Automaton and EPP is documented by Nominet.
I did it for fun initially (I know I have a strange idea of fun

) but then refined and tuned the code to catch a few names here and there for myself and my customers. Details of where people get their initial lists and how they tune their systems will of course not get shared with you as some people make good money out of their systems.