C'mmon, don't be shy.
We know you like teh white pocket square!
Ask what is possible, not what is predictable (but pay respect to the past!) . . .
If one is to own only ONE white shirt (such as for funerals and more formal events), what is the ideal shirt, in terms of cloth, collar, and cuff? I assume poplin or broadcloth, but would twill suffice? Is a spread or semi-spread collar conservative enough in an American context or should one stick to a point collar? I gather that a double cuff is preferable.