I agree with Skating Party.. just a lovely form.
The best modern white Iris come from Joe Ghio.
My Beloved has a perfect ruffled form, but I'm not sure if it's tall enough for your criteria..
A lot of people in our club have really embraced Battlestar Atlantis.. I grew it, and it's a good performer..
I've grown Lacy Snowflake for close to 30 years, so I know it's a survivor.. It's on the taller side.
If you wanted to go deeper into the historics, New Snow is pretty wonderful.. I recall it being very tall..
Snow Flurry, like Immortality has a blue blush when first opened.. It's tall and elegant..