2004 115 4-stroke trim guage

I have a 2004 115 4-stroke mounted on a 2004 Carolina Skiff 2180dlx and Im wanting to install a tilt/trim guage. I have noticed the switch on the engine and was wonderring if all I need to get is a guage to go in the dash? Someone told me that only a Yamaha guage will work. If this is true what is the part numbers for everything I'll need? Also is there a good website for buying Yamaha parts online? Any help is appreciated.

[boats.net]

Aftermarket trim gauges will work on 2001 and newer engines but you do have to install a wiring harness 68F-82553-70-00 between engine and trim gauge.

Can I buy that harness online?

[boats.net]

Yes they are available here at boats.net.