Sinead, I think you should definitely try a button down, though I'd try one with full length sleeves.
I'd also try a long-sleeve v-neck top, and then either a pretty necklace, or -if the v is small- maybe a little scarf.
Also, I think the jacket would also work without sleeves peeking out, but then I'd experiment with different necklines of the top. E.g., maybe you could try a v-neck sleeveless top with a necklace.
I'd say experiment with more options and post back some pictures!