I have a 1100 series bird mounted on the floor in the bow and used a traxstech track (thru bolted down) and a Cisco mount to slide into the track. This allows me to move it around a little and with it offset to the portside I can still run a trolling mast in the right side of the track when needed.
I have a 4 bank charger in the portside rear compartment so this allows the 3 batteries in the floor and starter in the rear starboard side and both storage bins will fit.
I am pretty sure the rear casting deck extensions can be ordered through a Skeeter dealer. I have seen some of them in the boats coming form Skeeter Boat Center. I’m sure a quick phone call can land you one from them.