Moran have an occassional chair that would work perfectly with that lounge. Its a design classic that work in everything from traditional, mid century to contemporary. Here it is.

Carter Occassional Chair, ignore the fabric, it comes in all sorts of fabrics. The shape however echos your sofa without directly copying it. This style of chair fits in many decor themes.

Maybe this from Adairs.

Thanks everyone - sorry it took me so long to get back to you! I read somewhere that you should match the arm heights with the sofa. I like the idea of cane and linen but I also like the Moran which seems like a classic that would last the distance. Maybe a classic chair for the bedroom and something light and easy to move around for the living room. I've been distracted trying out designs in room styler ;)

It looks like a really low sofa (back height). 2 considerations. One buy other furniture you like and make them the feature and look to replace sofa at some point to match. Or keep sofa as feature and buy chairs that don’t dominate space so light and small

I think a square, lower back chairs would look good, overstock