Sean, You can get a good 2.2 kw/ 16 inch radar at West Marine for about 1000 to 1200 dollars now. Black and white screen but a very good screen. These 2.2 kw radar are good up to 16 miles but more important are very good at close range. I can pick up crab pots and sea gulls when I am in the .5 mile space and can go down to I think .125 mile on the screen. They have all the bells and whistles like alarms for other boats coming into a set space. The program I like is distance to a certain point, I know GPS does this as well now but with the radar I can get direction a vessel is approaching at and its speed.
The single pole stands are more expensive than the radar but on a fishing boat it would be easy to make your own for a small price. You could also make it adjustable up and down in hieght so when it's not foggy out you can keep it lower. We will soon be buying a new radar and single poll mount for the new boat that has a few more than needed stuff on the pole. The boat had 24 inch dome on the mast which was good out to 24 miles I think. We just did not need that distance, it was too high for close in stuff and under sail it worked great for picking up air traffic to the windward side so we sold it. With the pole mount for the stern I can get manual tilt option to keep radar horizontal, GPS antenna stand, place for a cockpit spot light and a davit to lift the 8 hp outboard back on board. I like the 2.2 kw Furuno radar but they are all good now a days.