I need a Javascript poem/word generator building for my website.

I need something similar to this http://thinkzone.wlonk.com/PoemGen/PoemGen.htm

Steps

1.Customer chooses or inputs words
2.The programme will produce the poem/story
3.The page will show the customer a section of the poem/story as a taster
4.The customer pays
5.The whole poem/story is accessible for the customer to download and/or print for a limited period.

I will supply the databasewhich will be:
6 sections - e.g.
beginning
middle
middle
middle
middle
end

with 6 different variations of these for the programme to choose from, each about 40 words long.

in the 6 different variations will be about 5 words that will be inputted by the words chosen or inputted by the customer.

I have a php database and I am building the website with Wordpress so will need to incorporate this somehow.

Would like to know a rough idea of how many hours this can be built in.