You're welcome. I'm not familiar with the splines on a T5 input shaft as to if you can get a clutch disc in either 10.4 or 11 inch size. That is why I would check into that before buying the rest of what you need. According to what you are going to build I would use the smaller diameter set up as you mentioned; if you have a choice. In fact I am building about the same project. A 181 Merc, Saginaw 4 speed, rectangular tube Model A type frame, and a bare bones 25 T coupe body. I am using a light 12 3/4" flywheel with a 10.4 dia clutch disc. Overall I expect the finished job to come in around 1500 lbs. There will be nothing on this car that is not absolutely needed for driving and safety.
