Perfect Width and Offset? Options

[Random_Stranger]

Ok, I obviously know nothing about rims. I have decided to paint my car red in the future. It was originally red, and so was my GT4 hood and bumper prior to applying them. So now the riser blocks are going to go to black, car is going to be red, and looking for a new decent set of rims.

For our cars, what is the perfect width and offset to fill out and give a more aggressive appearance? Not so much opinion, but just what fills out the most. I don't mind if the wheels kinda stick out a lil bit, but I do want a more aggressive look with the rims and for the wheels to fill out that area a lot better.

If you have tire size suggestions as well for whatever rims, it would be appreciated. But I dunno how offsets go and such. I have seen some 18's x 8.5 with a 38mm offset I was thinking about. I guess the lip is 2". But I am not sure how it is going to look. So I ask you experts out there.

Thanks

[3TST]

Additional info. to help with calculations:
Model - Celica T20*
Year - 90 to 99
PCD - 5x100
Offset - 35 to 42
Bore - 54.1

The mathematical calculations will give you a safe bet.

The only way to really know is trial and error - cheaper to do this with 1 set of wheels and spacers

Failing that, I put some wheels on that I knew the dimesnions and then got the tape measure out.
Measured the inner clearance between rim/tyre to strut and then from rim/tyre to inner edge of wing.
Then did some calculations.