offset for 17s on a saph 2wd
 

i want to buy rota d154 wheels for my 2wd saphire cosworth, i checked all the sites and the availble dimension is 8x17 et42 4x108
will they fit ok to my car or i have to put spacers 7mm to have the et35 which is the correct ET for 17s in other makes?
there is also another option on rota 8.5x17 et35 4x108 this will be a straight fit and i have to go for 235 wide tyres?

thanks

On my car running std koni type struts on front 8jx17s were fine with 205/40/17s. et35. ive run tsw hocks with 215/40/17s there 8x17s et38. ive also run 8x17s on et40 with 205/40/17 all with no issues.. i think you can run bigger tyres if usen coilovers as you have no issue with strut platform catchn