I would say hold back a little and sow in stronger natural light and longer day length. Little will be gained by sowing now under lights, and may easily result in inferior plants.
Impatiens come in tropical to hardy - annual to perennial and sub-shrubs.
A striking perennial one to look out for is the 'Congo Cockatoo' Impatiens niamniamensis.
A garden bedding type is the 'Novette Series' which are fast growing perennials usually grown as annuals. There are many other series, varieties and cultivars grown annually from seed for summer use outdoors and most may be pot grown in cool conditions with maximum light.
Another spectacular species with silvery foliage and purplish-red flowers is 'Marianiae' It is tropical and will require a temperature into the 70sF.
There are countless cultivars within the group "New Guinea Hybrids" All should be good for indoor cultivation given a light spot but not in direct sunlight. They are perennial but often treat as annuals to obtain fresh, vigorous plants each year.
Grow Impatiens in a rapid-draining medium and water copiously during the summer months. Never let the roots stand in water. If keeping over winter reduce watering to keep the soil just moist.
When propagating be it seed or cuttings keep the temperature even; a fluctuating temperature is not good particularly at this time.

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Peter

If you supplement with flourescent lights indoors in winter, they should do fine. Otherwise summer is best.

Indoors, I water much more sparingly than outdoors, but I still use a diluted fertilizer with every 2nd watering.