The stern-mounted post would be an easy option since it doesn't require going up (or laying down) the mast. I have a close-up image that showed the name of the manufacturer:
http://www.questusmarine.com/The old Raymarine drew too much power and I think the low height was a bit closer to the helmman's head than is recommended. However, modern radar has much lower power emission, but I wonder how the mast and low height would affect the radar image.
I need to pull the mast anyway (to replace the centerboard pennant tube, so I thought that would be a good time to mount new radar. If I buy it ahead of time I could put it on this post temporarily and try it out. The new radar is pretty amazing.
The first image shows the gimbled dome mount pretty well...