I have the same boat, and the fuel tank was replaced by PO with a few "kinks" I had to sort out, so I have some tips to offer. It's a 25 gallon poly Moeller tank. You should be able to find a stock tank after taking proper measurements. A few things to note:
-the tank didn't fit snugly in the tank box so PO used some 2 x 4's to build a box that takes up excess space in back of fuel tank box. Nothing wrong with this.
-the new tank sender and hardware was not accessible with old pie plates, I installed new ones to make it accessible. Might want to do this at the same time as installing the new tank so you only have to pull that deck up once!
-The tank you will need is going to be pretty long and shallow. Leave yourself plenty of room between tank and deck. The one my PO installed is a little too high, and the fuel line and vent line are bent at a 90 degree angle and press up against hatch. This is a PITA because it keeps my new hatch from closing all the way and lets water in. So either leave plenty of room or put in a 90 degree elbow fittings.
PM me if you have any other questions, I also have pics and whatnot. Can probably find you a model number if need be.