+1 on Joel’s post.
I am running 16 inch diameter VTO’s in the Minilite style (the older superlite from Australia version). I think you will like the ride quality of 15 inch tires better. Going with only 6 inch rims in the front versus 7 inch rims will make for more enjoyable steering effort. Seven inch rims are good for the back. Just be sure you get the right offsets (back spacing) for front and back.
If you are like most Tiger owners, you do not put enough miles on your car yearly to make mileage rating relevant. Tires will probably get too old before they wear out, so get the best gripping tires possible. I have Dunlop Direzza Star Specs on my car.
Correction, the Dunlops are on my 15 inch street class autocross wheels. I have Michelins on my 16 inch street wheels in sizes no longer available. Like the Dunlops better.