will these two options work on my is300... If not what needs to b done to fit it.. Thx in advance

17x9 +20 all around?

on stock suspension work?

17x9 +20 all around

on tein spring drop..

1.3" in front 1.6" in rear

 

The size seems good since its near stock. The offset is a bit to aggressive, which may require fender rolling when you're doing a spring drop. I think you'll be fine if you have a stock suspension.
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My fitment
18x9.5 +12
18x10.5 +15

 

so ur saying if i stay on stock suspension they will work

but if i drop the car with springs.. im goin to need to roll fenders?

what would b a good tire size to go with?

 

so ur saying if i stay on stock suspension they will work

but if i drop the car with springs.. im goin to need to roll fenders?

what would b a good tire size to go with?

 

If you're gonna stretch your tires, I suggest using tyrestretch.com
You can see how it'll look like.
Going from smallest to biggest in stretch
205/45
215/45
235/45
Or you can just find the right size that would fit the rim perfectly. Stretching tires is cheaper, and in most cases, it will help with the tire not rubbing on the fender.
I think 245/45 would fit your rim the most.