Um, if you already have a Magni for your primary use case, then do you really need to upgrade your speakers?
Here's what I'm thinking: if you use my system as an example, you might notice that a Schiit headphone amp is my only amplifier. I have a pair of B&O powered speakers from a previous audiofool stint, and I just plugged them into my Valhalla's preamp out. The few times I don't want to use my headphones, they're good enough.
If you're planning to continue using your headphones, then it might be a better use of your money to optimize that path and keep your current powered speakers for now.
If you need an input selector, then $10 or so on Amazon will get a no-name switch that you can pair with the Magni.