295 vs 305 on 21's again.

[Oompah]

Hi all, 

Got a set of BBS RX2 in 21 
front et23, 9j 
rear et28, 10.5j 

At the same time as sorting out the wheels, I will install KW HAS, so I am trying to avoid any issues before spending money on mps4s. 
I know there is millions of threads around tyre/wheel combo but I don't seem to be able to find a definitive answer for me. 

I am thinking of going 265 30 front and 305 25 at the back but I can see straight away that front will have to get around 7-10mm spacer because of the brake caliper. 
I don't expect the rear to be a big problem in terms of caliper clearance but maybe someone could let me know if I would be better of running 295 or 305 with this rim setup and KW HAS on as well. 
"Will they fit" says using 305 will up a little tyre height (6mm) which is great because I worry a little about potholes and the condition of UK roads all together. 

Don't want to play with camber or see any rubbing. 

Any thoughts? 


Thanks