read this page about offsets
Stock offset is 47mm
This means the centerline of the wheel (as viewed from above with the tire rolling) is 47mm away from where it is bolted to the hub. So, think of it as negative offset.
I believe 35mm is the lowest you can go
This would relocate the centerline of the wheel 12mm outward. this is ok if you are using tires that will be no wider than 24mm+stock. Get it?
If you are looking at 245mm wide tires, they will rub with an offset of 35.
205(stock)+24 ~ 230 (you could go a little higher that this as there is some extra room even with the stock tire setup). Maybe 235?? Also, the fenders need to be rolled.
Keep in mind that more offset will allow they to fit, but put more stress of all of your suspension. Also keep in mind that fat tires will cause the car to pull to the side when driving on an uneven road.
9.5 in rims are 241 mm wide themselves. So this is not possible without using low affsets and spacers/longer wheel studs.
8.5 in rims = about 215 mm wide, so fitting them with 235 wide tires (with a 35 offset wheel) should not be a problem even on the front with extra weight and hard cornering.
Maybe think about 8 in the front, and 8.5 in the rear. Again not to say that 9.5 WILL NOT work, it will just take more work and money on your part to do it right!