fishfinder only or fishfinder/GPS combo? Mono or Color?

I'd second or third the Matrix series- i'm on my second 17, and it lasts and lasts- despite being hammered (i'm a HOE...Hard On Equipment) constantly. I'm always ending up with the contacts on the wire at the battery corroding- despite using ample dielectric grease - mostly cause i'm almost completely lazy and rarely hose the thing down, and have yet to build a decent waterproof battery ( i just toss an old lead acid in the hull with the contacts bare).

Ive' got the GPS receiver that goes with it-- both deck mounted.  I don't think you need maps with your GPS, they're nice, but waypoints do you just as well, especially since its not like we're padddling tens of miles from a launch.

Stache54, do you mind elaborating on that computer 12v UPS battery? I've been looking to improve my setup.

Calbear,  I am using an APC RBC46 12v battery inside an UltraBox 406 drybox I got from liesurepro.com ( http://www.leisurepro.com/Prod/UKT406.html ) I got the 2 wire connectors from Radio Shack and a waterproof switch I found on eBay, drilled holes in the box for the switch and wires and used marine Goop to seal the penetrations.  The wire connections were soldered then covered with heat shrink tube.  I put adhesive backed velcro on the bottom of the box and on the inside of my kayak hull to keep the whole thig in place.  I recharge the battery with a motorcycle battery trickle charger, and the unit will run for several days of fishing on a single charge.  Check out the attached images.