would you choose between Bressingham Blue or Blue Angel? I would like a large blue one, maybe someone besides either of these two? Are there any blues that stay blue all summer or even with some sun?

I do not have it , but saw a couple of Hosta Blueberry Waffles. Very nice blue color well into the season. Do not know how much sun it can handle.

I really like Powder Blue. This picture was taken in July of this year. It's in a shady spot, so it stays blue most of the season.

If it could have a small central variegation on a blue background, you might consider Touch of Class. It has a very heavy substance and stays beautiful longer than most other hostas.
Hosta 'Touch of Class'

Silver Bay is the bluest of all my blue but it's closer to medium size.

Blue Angel.