One of my favorite standard hybrid is the Starlight Green Egger, I've got one now named 'Honey' and she lays the most GIANT near-olive green eggs...it's beautiful!
If you want to, you can breed a bantam rooster to a full-sized hen. Chicks will probably grow up to be medium in size. Females from that can be crossed to a bantam rooster, and some of the next generation should be smaller.
Of course you will have bantam-sized chickens faster by just breeding from bantams, but if you enjoy breeding projects and like the traits of your current hens...
I think aside from egg color and bantam size, I'll prioritize social, friendly birds.
I'm not so much concerned about henny noise considering I'm surrounded by many neighbors who don't seem to care whether their neighbors mind incessant, non-stop barking (shrug). I won't be letting a rooster crow, however...we'll reserve that for inside or in the garage turned chicken hotel.
You might think about whether you want extra feathers and fancy traits (crests, feathered feet, muff/beard on the face, sikie or frizzle feathers, extra toes.) Some bantams have them and some bantams do not. Silkie feathers are recessive. If you cross a Silkie with something else, you get chicks with normal feathers. The others are mostly dominant traits, so they tend to show up in a first generation of a cross. If you breed the mixes to each other or to another "normal" type chicken, you will get some without the extra traits.
If you want to avoid broodiness, you can selectively breed among whichever chickens you have (mainly a matter of hatching eggs from the hens that go broody less or not at all, rather than eggs from the ones that go broody most often.) If you like having some broodies, then obviously you do not have to do that.
I assume you know that hatching eggs will give you a bunch of males as well as females. I hope you have a plan to deal with the extras. Bantams are just as edible as any other chicken, if you want to eat the extras. They're just smaller.