Sat Nav for Warrior 165

I was thinking of treating myself to a new Sat Nav and was wondering what is popular at the moment. The old Garnin has served me well but there are a lot of fancy new toys on the market, any idea would be grateful

I've got a Garmin 550 (now updated by the 551) in my 165 and I can't fault it.
It has an internal antenna so no new holes to be made.

The SD card is an excellent feature when matched with Garmin MapSourse installed in your computer.
You can edit, delete and install waypoints at home and reinstall them into the Garmin 551 the next time you’re at the boat.

I've got a Garmin 550 (now updated by the 551) in my 165 and I can't fault it.
It has an internal antenna so no new holes to be made.

The SD card is an excellent feature when matched with Garmin MapSourse installed in your computer.
You can edit, delete and install waypoints at home and reinstall them into the Garmin 551 the next time you’re at the boat.

Are they easy to install or would I be better getting it fitted.. its to replace an old Garmin 128

2 screws to mount it on the consul.
2 wires to connect to the fused switch
built in antenna no wiring to be done

Great, it sounds easy, thanks for your help