Mounting Humminbird 859ci HD Combo on bow of Carolina Skiff 178dlv

My dad and I recently purchased a 2009 Carolina Skiff 178dlv. Today I will be mounting a Minnkota Terrova 80# thrust 24v, with universal sonar 2 and iLink. I will also be mounting the hummingbird 859 on the bow. I am trying to determine what is the best way to mount the depth finder. I will have 2 batteries at the bow, but they will be connected together to make it 24 V. I need to figure out how to power the depth finder. At least I don't have to worry about the transducer because it will be connected to the universal sonar. Any advice is appreciated.

Also, what would be the best batteries to use for the trolling motor?

I could be wrong but I don't think the 3d 859 HD di will hook to the 2d sonar. Hopefully one of the other guys can help and chime in

is your 859 di or just a 859 ?

It is the regular 859ci, no DI or SI. I knew that would not work with the universal sonar, so I did not get it with DI or SI

Go to Walmart and get a pair of group 31's from there. Far as mounting finder I don't know the layout of your boat so hard to recommend how or where to mount. Can you shoot us a picture?