If u are going for non staggered, your choice will be much more limited which will also make your selection easier in a way. Firstly, using front as a guide, u can choose either 8.5" or 9" width. Going too wide will have knocking issue when turning. Next is offset. Depending on how flush u want and whether u are going to lower your car. If you are not lowering your car, the following should work.
19x8.5 ET30
19x9 ET35
20x8.5 ET30
20x8.5 ET35
For tires, it is another calculation. You will need to ensure diameter stays near our stock setting of 660mm. For eg choosing 255/35/19.
Hope these help