Doors of Durin Arch

Hi there,

Newbie to the forum and amateur woodworker. I have a project on my hands to do a 'Doors of Durin' archway and I'm looking for a little help on it. The design is attached, as well as a picture of the doorway, above which it will be placed.

This is to be fixed to a wall, it's almost 2 metres in diameter and 1m in height. Ignore the stars and crown in the design, just the arch. It will clear the lamp above the door. If you know the Doors of Durin, I'm not doing the side columns, it can't be too expensive or lengthy a job.

At the moment, I was thinking of doing the arch and letters separately; the arch out of 12 or 18mm marine ply or similar sheet material with a raised trim top and bottom, and the letters out of another sheet and glued/doweled onto the front.

It's the letters that are the headache. I'd like some contrast between the letters and background. I have a router and jigsaw which should get me through the cutting; I'd rather not do a relief carving of the letters with the router from a solid piece btw, I'm just picturing a world of problems with keeping the same depth for the background.

So I'm thinking one option might be to cut the letters from a sheet of MDF; it'll give a clean edge, I can paint and glue on the front face easily.
Another option else would be to use some other type of wood, just not an edge-glued sheet and not pine - it won't be able to handle delicate letters and will end up breaking/snapping on me.

Q: For this other type of wood, would hardwood be suitable to cut letter out of? Will it break? What kind of wood should I use?

Q: How would you approach this? Does this sound like a decent plan?

Thanks in advance.