Which Onion to grow from seed?

I'm no help, my red onion sets always bolt so I've vowed to give up on them. I've never succeeded with seed. I do have some winter onion seedlings (senshyu?)growing in the patch but I bet this weather has done for them. I can't go and check on them as the grass is all frosted and would be damaged by my footprints, they'll have to wait until the thaw.