What would you guys think is better for a 9' pelican fiberglass fishing boat, a portable fish finder or one that is mounted? I do a lot of bank fishing too since Its hard for me to transport my boat, but do can you use portable just as good as mounted on a boat? Thanks!

You can get a portable Eagle Cuda or Hummingbird unit, the transducer is attached to the hull via a suction cup. The unit works with batteries ( D size ) but if I 'm not wrong you can power it with your TM battery with an adapter.

Beause you still do a lot of bank fishing I would go with the Portable unit.  That way you can use it at any time that you fish be it from the bank or from your Pelican.