I agree of the second photos, the dark with gold head is a Golden Sebright. They can go broody, and be good mothers, but they are so small that you can't really put much of anything under them by way of large fowl.
The second bird, the buff, I believe is a Bantam Buff Cochin...as I think I see a single comb in your first set of photos for that chick. If it is a single comb, you've got yourself a Bantam Cochin.
Now in the Bantam Cochins, the males will telecast early by comb development. You will strongly suspicion by 4 to 6 weeks and know by 8 to 10 weeks that you've got a male if that comb takes off and gets big, then rosey red.
Females will stay small and pale yellow maybe getting a bit peachy by 3 to 4 months.
If you've got a Bantam Cochin (which I think you have), and it is female, you've got yourself a good chance at a broody hen as Bantam Cochins overall make good broodies and mothers and are very sweet and docile. Since they are mop like fluffy, you can easily put 4 to 6 large fowl eggs under them with success (remember the gal I got my bantam Cochins from was using them to hatch turkey eggs!).
If you like working in smaller batches, a good bantam Cochin can brood 2 to 3 times a year. A good Silkie will brood 3 to 4 times a year.
I do recommend creating a separate brooding and grow out area for your little bantams to do their mothering business. Bantams often get no respect from a big flock, which can upset the mothering and endanger chicks. Plus, with Cochins and Silkies, the feathered feet can be a magnet for bumblefoot if they are tromping in muddy ground with the big girls.
I'll post a photo of my set up created from old shipping crates and set on top of an old grape arbor. We then strung up bird netting and chicken wire to create a secure run (I've got to get an updated photo as we have our really nice canvas tarp over the run now...what's in the photo was a temporary tarp).
Keeping my fingers crossed that you've got a girl and she's got good brooding genetics.
Inside the broody hutch...you can see the double ends which have 2 separate nests...I have a wire insert that can divide if I need to
Finishing the run...temporary tarp up to keep bantams drier (important for the feather footed types)
They'll even brood in winter for you (without heat)! Babies run around in their little down jackets then duck under momma for a warming hutch. They'll be out scratching at day 3 or so! (Blows your mind when you think how hard you worked to keep those heat lamps at just the right 96 to 98 degrees).
My most recent hatch produced just one chick...these Bantam Cochin sisters went broody together and I think exchanged eggs a little too frequently letting the eggs get cold at times (all were developed, but some stopped growing or developed fully but never hatched) as I found eggs in between the girls a number of times. Normally I separate brooding hens to prevent such stealing and leaving eggs on the fringes, but thought I'd experiment to see if these two could co-brood together as I already had the Silkie with her grow outs on the other side of the hutch.