Are you using NRaas StoryProgression? If so, you can use rapid immigration to add however many households you want. All the relevant information for it, and for SP immigration in general, is here:
http://www.nraas.net/StoryProgression-FAQ-Immigration
You don't need to worry about the immigration gauge; just look at the second section. I'd suggest saving a number of households to the in-game bin so SP has bin sims to draw from. Since your town won't have any residents yet, SP won't be able to draw genetics from the town (except from your sims, which you might not want), and the EA option produces zero-slider sims. If you set the chance of bin offspring to 100 and the EA option to zero, or something close, SP will use the bin sims' genetics to generate the new sims.
If you don't use SP, I'd just save interesting sims from other towns and place them in the new town. If you let EA immigrate in the sims, they'll all be the usual zero-slider puddingface types, and that gets boring quickly.
