@jasonbourne52. Thanks for the suggestion- It's a really refreshing and reasonable option for powering a 4 ohm speaker.
THANKS to all of you for your thoughts and targeted steering. I've had a good time researching all of the leads mentioned here. Crown amps have prompted the most comments, and are the (controversial!) value choice! In a middle price range, the Bryston and Oddessy offerings make a lot of sense- and look to be a good match for the quirky Magnepan load. If I decide to splurge, the Parasound Hint Halo or a Hegel integrated look really attractive too . . .
Today, I'm leaning towards the Odessey Stratos (150wpc at 8 ohms): Love the reviews, the 20 year warranty, the long term manufacturing experience on their product line, and their focus on made in USA. At $1,400, it leaves room for some decent cables.