I'm planning to get this BBS LM 17" rim. The size are 17x8 offset +40 and 17x9 offset +42... I want a flush look, will it be okay with my car?

 

there are several things that you're going to have to take into consideration for it to be "OK"

1. camber - you are going to need to camber the wheels to get them to sit "flush" with the fender no matter what you do. but the next couple of things on the checklist will determine if you need more camber
2. ride height - the lower you go, the more camber you will need (if you want to tuck the tire, etc)
3. tire size - you can either run a meaty tire or a stretched tire. if you run a...lets say... 255/40, you are going to need more camber as the tire height on the outer-most part of the wheel will be taller than it would with lets say a 225/40
4. rolled fenders - if you have your fenders rolled, it will make it easier to fit the wheels. you can get into crazy fender rolling/flaring, but youre gonna need to get it repainted

 

what is the correct offset and tires 17 " for an s2000 without all this fender rolling crap, I just want to buy some wheels and not worry about all this extra crap

 

^^^stock is correct...

 

Just get 215/45 up front and 245/45 in the rear, don't slam it, leave about 1 1/2 fingers in the rear and you'll be fine.
I just did that with kw v3's, rpf1 17X8 +45 17x9 +45 and im more than happy..but i won't lie, i plan on going with 225/255 next time around.

 

BBS LM's is a sweet wheel