Im a distributor of BSR in Poland, and we mostly use pink or white rears, and purple or black fronts.
Some drivers use xxpink fronts ( which are like crc magenta) but that’s combination for a high grip track and the use them with pink rears.
According to batteries , most drivers decided to use 4200IB batteries, and after that we changed for 4600 as they became evadible. But the firs packs were as some would say "rubbish". You were lucky if you could make two 4cell packs out of 12 cells. ( working cells not some super matched cells)
but that was just in order to get several extra seconds of run time.
Now when most cell have been improved i would rather recomend for 12 class 4600 IB. Or EnerG 4600 I have no opinion about them but can be worth of testing.
For a motor I would recommend 5,5 turns , or 4,5 because 5,5 might not be fast enough for some tracks. If you have a long “straight” you would get your ass kicked. Some drivers prefer to use low turn motors , even in order to save batteries, they claim the just don’t have to squeeze the throttle that much all the time.