The NAD was a T761, which turned out to be very poorly built. It was universally hated by its owners. I believe it had about 100 wpc. But all watts are not created equal. My Jolida puts out 70 wpc, yet it plays louder, with far less distortion, and much more bass authority and control.

A well built SS amp should not be an issue. It's better to run an amp well within its parameters than to push it to its limits. You can always ask the store to hook the maggies up to your amp and see what you think. If they won't, see if you can do a home trial. And do yourself a favor and listen to what they can do with a quality tube amp while you're at the store.