Anyone know how wide of a rim you can go and what’s the lowest offset at stock height?

Looking at running
18x9 32offset front
18x10 38 offset rear

I want a deep dish concave look if anyone can help

 

For the front you won't want to go more than 9 inches.
+32 offset isn't bad, a +35 would be better...but you have to consider what tire size you're gonna use.

For the rear you could go up to 10.5 inches...but you'll need a +45 offset at least. With a 10 inch +38 you might(probably) get rubbing on big dips/bumps...once again, depends on tire size.
Ideally with the 10 inch you wanna be about +42 or more.

 

been offered a set of 19" with Fronts 8.5 et35 Rears 9.5 et40 would these sit out enough on the rear cheers paul

 

It would be an almost (like super close) flush fitment on the rear...front would be fine.