looking for ideas on fish finders , which brand, model and how its installed, mainly transducer location and installation

It comes down to how much you want to spend or make do with leftovers you already own. Most people mount the transducer to the trolling motor on the bow and have the head unit mounted to one side or the other on the bow. You can use a stainless steel automotive radiator hose clamp to attach a transducer to a trolling motor. I have also seen it attached with zip ties.

I didn't like my Bass Raider twirling around in the wind so I cut out a wooden rudder and fiber glassed it to PVC pipe which went into an upside down adjustable flag pole holder which was attached to the transom with 4 stainless steel screws. Later I cut out a section of the wood rudder to mount the transducer so it would not hang underneath the rudder and be somewhat protected. I kept the battery in the stern of the boat and ran the power cable and the transducer cable up the side of the Bass Raider to the head unit mounted on the right pontoon bow. I am left handed so the fishing rod would be in my left hand and the right hand would control the trolling motor and fish finder.

Whatever you do, don't drill any holes below the waterline.
I hope this helps.

Mount the transducer at the bottom of the trolling motor where it is clear of the prop. Use a large hose clamp or heavy duty zip tie. Zip tie the cable to the shaft every 6 inches or so as you go up. You can attached the head unit to a piece of PVC or thick wooden dowl that will fit snuggly into one of the rod holders, this way you can remove the head unit easily when storing and the tranducers always stays with the trolling motor. I use the same power source as my trolling motor.