How Big should I go

[MDellboy420]

I have a 90 mk3 supra with a single turbo 2JZ, the stock wheel setup and suspension gives me nowhere near enough traction, im about to get new coilovers and rims but i dont know what size to go..people are telling me to go with 18x9 in the front and 18x10 in the rear or 19x9 and 19x10..Im not sure what to get cuz i dont know how big i can go without messing up the ride..what do yall think would be the smoothest ride and best bet