With a 215/35/18 tyre and after the suspension settings were all done right, it doesn't scrub now.

would 17x8 +35 all round fit well, not sure on tire sizes...

Non staggered wheels never fit well on an SW20.

Non staggered will work will work well on an SW20 providing;
> The fronts fit without rubbing.
> The fitment front and rear will give you enough adjustment for a good amount of negative camber.
 
I had Nissan Skyline R32 GTR wheels on my SW20 and they looked great. Unfortunately, there needed to be a bit more guard manipulation than what I was prepared to do to get a decent amount of negative camber on the front.
I've gone back to R32 GTST wheels on the front.
 

if you put wheels spacers on the back does that help?

It does, but then you want make sure you still have the wheels sitting on the hub and not just hanging off the wheel threads. you also need to make sure you have enough thread for your nuts if youre spacers are going to be more than a few millimetres. 
 
Personally, i'd just buy some wheels that fit properly that go through all these work arounds to fit a set of wheels that aren't right from the start.

Wheel spacers:
Insurance could be voided if you put them on, and I believe they are illegal in all states anyway.
 
Maybe do some Googling to find out more, especially about insurance, for example:
http://www.toymods.org.au/forums/threads/71185-Wheel-spacers-illegal-in-Victoria
 
 
 

Reddtarga
Wheel spacers:
Insurance could be voided if you put them on, and I believe they are illegal in all states anyway.
 
Maybe do some Googling to find out more, especially about insurance, for example:
http://www.toymods.org.au/forums/threads/71185-Wheel-spacers-illegal-in-Victoria
 
 

 
 
As I always say, and it probably bores people to tears - keep your mods legal.
You may only drive the car once in a blue moon but if you get pulled over in some, "Keep the streets safe from cars with too much low/big exhausts kill puppies so ban all cool cars" traffic blitz you could find your car being put up on some mobile hoist and having EVERY 'defect' and non compliant mod (and some listed on the sheet by the copper/inspector who isn't certain but thinks 'its not right') written out on some big long form that you can barely read, a bright yellow or red sticker on your windscreen and a fistful of tickets. And not tickets to the latest movie. 
 
Or be like some who have their mods approved on paper, or just keep the mods to something that doesn't need an engineering cert. Then when/if you get stopped, let them poke over the car as much as they like then you can resume regular life. Believe it or not, some traffic/hwy cops do that job because they enjoy cars and mods as well, and no surprise that some of them are humourless ticket machines. 
 

hey guys, how does 16x7 +10 and 16x8 +10 with 205/40/16 for front and 215/40/16 for the back sound? Any issues?

Should be ok. May poke out a little.
 
A +20 to +30 offset front and rear on a 7" 8" would be safer if you don't want to poke out the guards.