i have a chance to get ex-box for way too low $$$ but from s2r 1000,I have S4RS so my question is if i buy
ex-box mid pipe for my bike (S4RS) and fit on the can from s2r1000 will that be ok???

p.s. my english sucks so i'a, sorry 

my understanding is that it's a different diameter, off about 10 mm I think.  however, the under tail exhaust will fit the cow udder and vice versa.  In other words, you can use the S2R exhaust cans you have (Termis for instance) and go directly onto the udder.  This is what I did and I plan on fitting a mid pipe soon.  I was told my a tech at Motowheels that the setup you're trying to run will not work. 

i ask my service and they told me if i get pipes for s4rs then it wont be a problem

so now i'am little 

The ex box is instead of mid pipes = mid pipes have nothing to do with an ex box. Mid pipes are used between the cylinders and mufflers (other than an ex box).

The S2R ex box pipes will not fit the cylinder head on a S4R. You can cut the pipes and have them welded in a "S2R ex box/S4R pipes" configuration, but that will probably be expensive.

I suggest: keep looking for a S4R ex box