Fronts are easier. There are lots of 225-50-15 v or better tires around.
I have Pirelli 225-50-15 P7's on the front but I am going to replace them with something larger. 235 will definitely fit. Some say a 245-50-15 will fit as well.
The largest problem is the lack of something better then an S (BFG) or a T (Mickey Thompson) for the rear.
The BFG has a wider tread at 12.2". The Mickey Thompson tread is a 9.7" tread according to the chart. That would give you the look of a Bonneville vintage 1964 over inflated tire, which I am sure was intended considering it is Mickey Thompson.
The 225-50-15 fronts look like go cart tires on this car and have the effect of lowering the front a little.
Too bad the P7s aren't available. I think they were the best of the 15" tires.