I think plan B would have to be the easiest, but you'll have no sunroof - must have sunroof
And from what i know of roof conversions and such (plan C), the cuts have to be right on the money and not a somewhere close cut is good enough. And your talking about swapping one roof, above the pillars, from one car to another car. Thats going to be a shut load of measuring, re-measuring and re-re-measuring between both cars.
Plan D you could visit the wreckers for another roof, cut that one on the pillars and it'll be one less step that you'll have to worry about.
Plus you have a sunroof.....