I'm not 100% sure about what I did because once I got all the items I didn't need to hire the people anymore. Once the building was done I didn't need to ask people or hire. I used the unlimited items by pwnthis "http://www.pwnthis.net/2011/01/cityville-cheats-unlimited-items.html". But I guess you can also use the others unlimited items cheat and I believe there's also a plugin.
Here's a picture of my buildings which is a hospital and a( I forgot the name)