20” will work…add length and width and convert to inches.

Keep in mind your front door glass and the stained glass over the window. The door glass is Art Deco in style and the stained glass is more turn of the century. Add to that the stair case is typically Colonial in style. So, I’m going to suggest this pendant from shadesoflight.com.

Is there a basic color that is in all? an amber or bronze seems in rectangular border.... maybe bit of that... seems option is too casual. Does rest of the house have any distressed wood surfaces?

Let's talk shape, and talk finishes....this reminds me of simple lines of one you like. If floor tile is informal, maybe a non-fancy light?

H 30" x W 28" Iron in antique rust color.

Legion Furniture Tessa Chandelier · More Info

https://www.houzz.com/products/legion-furniture-tessa-chandelier-prvw-vr~99371796

... if you like all these busy little lights - what about burnt sienna? I think a cool finish could be a 'relief' and 'invisible' a bit.

W 20" / H 38" /

Sea Gull 51317EN-965 Eight Light Hall / Foyer · More Info

https://www.houzz.com/products/eight-light-hall-foyer-antique-brushed-nickel-prvw-vr~84226703

The pendant is the best looking one.

The floors will be distressed hardwood and stairs will be redone to match. I’m really just unsure of size.

What about this?

with distressed wood the round one or the this one. Are you going to make the floors with like driftwood colors?

Idk you were redoing floors.. anyway, with a grand foyer of 2 story and all the glasswork, I don't see that informal a light....maybe the rest of the house if a certain style....then a basic informal rug.

Floors first? maybe then you'd like a medium stain on the door.

The size will work great, go for it if you love it

Either one you posted will work. The fixture is up so high the only time you are really going to look at is coming down the staircase you seem to like the distressed wood and black iron so maybe do iron on your staircase or paint the spindles black and banister white rather than stain it