I have 19" staggered rims, 8" on front and 9" on rear. If I change to non staggered is there anything to consider other than all 4 rims being the same size?

Wil 9" rims work/fit OK on the front?

Will 8" rims look OK on the rear?

Any idea what the min/max offset is that can be used on both the rear and front?

 

9" will work on the front, depending of offset.

For a brief period I had the 9" rears on the front of my car, and the 35mm offset is just about the max. The OEM 9" fronts are a 25mm offset.

The OEM 8" wheel was a little skinny for the back, IMO, although I suppose you could use a spacer on the rear to improve the look.

If you find a 9" with an offset between 25 and 35, it should be fine.

 

Looking at a set of 18/9 with 24 offset. Plan to use 255/40/18 tires on all 4

 

That should work well, it's pretty close to the stock 20" front wheel width and offset.