These appear to be west elm circle cut out chairs. I don't think they in the online catalogue anymore, but I did a quick search and it looks like some sets are coming up for sale on other sites.

Before replacing your curtains as this can be quite expensive for such a large window, if they are in good condition, add a band of extra fabric to the bottom in what ever suits you, your existing curtain track can then be moved up to the ceiling for good looking full length curtains without the large round eyelets, could save you a lot of money, I would look at replacing/removing the sheers cheers

It's lovely but sadly no. Feel free to have a look here for white chairs, you might find an alternative - https://www.houzz.com.au/photos/products/query/white-chair/nqrwns 

Maybe try Asian/Balinese style business or look at pinterest: that will give you idea that you could take to a tradesman and get a quote on bespoke or if you have a male that is very handy some great ideas on that link. https://www.pinterest.com.au/pin/419679259009258301/