Last year was my first year wintersowing and I had good success with Snapdragons. Also, I had petunias volunteer from the year before so they might be good for wintersowing also.

As for starting indoors...I started amaranthus, celosia annual salvia and marigolds. I also had some morning glories in pots with supports to climb up but they didn't do as well as the plants I put directly in the ground. Maybe needed a bigger planter? Also basil looks good in containers.

Hope this helps.