I think that the plants you are talking about are Pelargoniums. These are frost tender aka half hardy perennials. I do do not know enough about zone 7 but as a general rule if the Winter temperature does not fall below 5 degrees Celsius (40F) then your plants should be OK.
Yes you can pot them up and bring them indoors for the Winter, you can also take cuttings. If you do decide to bring the plants indoors or to take cuttings treat the plants with insecticide and fungicide before transporting them. If taking cuttings two things to remember 1) Do not used any rooting compounds and 2) Do not tent or enclose your cuttings.
Hope this helps
Ron

Or you could try perennial geraniums, there are many wonderful types. They dont get as large as annual geraniums, but are very hardy and many easy to grow.

Jen

If you bring them in for the winter make sure to keep them in a sunny window, keep them barely moist and use a weak fertilizer every week until growth resumes in spring.