Have you tried a visit to the Nordstrom in your area? In terms of brick and mortar locations, they tend to offer the widest selection from the greatest range of brands. I also know that they have fantastic customer service, which, to be honest, is the most important thing to me.
I don’t know personally know any lingerie boutique owners in the Minneapolis/St. Paul area, so I’m also reluctant to refer you out to someone I’ve never met or interacted with before (especially since the same brands most boutiques carry are also in Nordstrom).
In terms of underwired brands I like, my favorites (like Kiss Me Deadly and Love Claudette) actually aren’t carried in most stores! :-D
But I also love Betsey Johnson (particularly their demi cups), Simone Perele (ask for the ‘Nina’ style), and Elle Macpherson (particularly the ‘Dentelle’ range). And if you change your mind and decide to try another soft or wireless bra, Cosabella makes some really nice ones.
Hope this helps and happy shopping!