I have a 2002 2510 WA and ended up installing a full set of Raymarine electronics (radar, FF, GPS/chartplotter) with two separate 7" displays. One display is a grayscale FF with chartplotter capability. The other display is color radar with chartplotter capability. The GPS antenna is SeaTalk, so it drives both displays. They are both HSB2 (high-speed bus), which means they are on a local area network, and can share data. Because radar works great on grayscale, I move the radar window to the grayscale display, and keep the FF and chartplotter on the color display in a split window arrangement. Works very well for me and I'm very happy with it.
The new Raymarine technology is awsome. But so are the other companies. Furuno makes stellare bottom machines and good radar also. I believe Garmin is begining to catch up and offering radar/ff/chartplotter multi-function systems also. Not sure of their quality or reputation though.
Can't go wrong with either Raymarine or Furuno.
WRT mounting the FF transducer, I opted to mount it on the back of the transom. I mounted a 3" x 8" x 1" piece of starboard onto the transom with 6 screws, bedded in 5200. The starboard was also bedded in 5200. The transducer got mounted to the starboard. When it comes time to change the transducer, I don't have to worry about multiple holes in the transom. Somewhere around here in the projects forum are some pics of my ride showing the ducer, the trim tabs, and the hydrofoils on the motor anti-ventilation plates.