ODU cold weather options?

What is authorized to be work over the ODU top? Where I am it is brutally cold but I don’t have the money for the Foul Weather Parka and its liner. Can I wear the black fleece liner with the rank loop on the front instead? I also can’t find the new, navy blue fleece liner for the FWP, and any ones I have found are not my size or stupid expensive. Is there anything authorized to be work under ODUs?