Coleus is easy. I have over wintered the same plants several years in a cool bedroom. You'll be amazed by how huge coleus can become when you keep it growing year after year. They are also easy to root from cuttings.

SPV was a little trickier for me. My vine cuttings didn't do so well inside the house, and I wound up throwing them out. That was surprising since they practically root over night. I have had several SPV come back in pots of other plants they were growing near when I dug the plants for winter (elephant ears and hibiscus). The vines stayed dormant until spring, then popped up unexpectedly when the temps got warm.

I have also dug the sweet potato tubers and stored them inside just like regular potatoes. You'll be shocked at how many tubers each plant has produced! They were very slow coming back the next year after planting them outside in early spring. It seems like they didn't sprout until July -- much too slow for me for the trouble. Last year I over wintered a couple of pots of sweet potato vines in the greenhouse and they did fine all winter.

I have a funny story about saving sweet potato tubers. One year I had my ornamental sweet potatoes dug and drying out on the lawn before storing them indoors for winter. I looked outside and saw our calf had some how gotten into the yard and was busily eating something. I ran outside to see what he in to, and he had eaten over half my sweet potatoes. I guess they are as edible as the regular orange sweet potatoes we eat. At least he thought so...