Long fitted white shirt with collar

[atosilis]

Think Pulp Fiction, I would like a white shirt that I can leave the top buttons undone and roll up the sleeves. I'd like to be able to wear it to work, untucked, with skirts/capri pants during the summer. Untucked shirts always look untidy so it needs to be fitted and smart. I'd like to buy about 3 so that I always have a clean one so it can't be too expensive. Can I find it? No.

Any ideas?

Oh, and it needs to be long enough not to display yards of my bum/back if I need to bend/stretch for any reason.

I tried a lovely Max Mara Weekend one on the other day but it was a tad tight and they didn't have the next size up. More of a tunic than a shirt though, so not sure if it would fit the bill (definitely wouldn't display anything you didn't want though!)