Toubkal in winter is cold but not toocold, especially because of how sunny it tends to be in the Atlas -- I spent 8 days in the CAF hut in March of this year and we had wall to wall blue sky 80% of the time. I wore a base layer, fleece midlayer and ME Fitzroy throughout the trip, and in fact was fine with just two layers a lot of the time. It's extremely dry in the Atlas so a feather down will offer a better warmth-to-weight ratio and will be greater value, but synthetic will be better in the long term if you intend to use it at all in the UK. Personally I'd recommend a Fitzroy, or a Citadel if you intend to go anywhere colder in the future.
We were there in February, it was around -10C at the refuge overnight but it wasn't any colder than a Scottish winter day on the ascent the next ( admittedly perfect) day. If you'd be comfortable on Ben Macdui you'll probably be fine on Toubkal. Also worth noting that it'll be T shirt weather in Marrakesh by then (at least for a pasty Scot like me) -its lovely there in February.
Edit - the sun is mighty strong up there though and you wont be sorry to have goggles for the couloir.