For the main alternator feed to battery something like 44/030 or 56/030 cable is normal, but some use 84/030 or even 97/030, personally I'd use 56/030 thinwall, this carries 39 amps continuous, about 70p/metre.
For battery to starter/earth I'd use 196/040 or 315/040, £4-£5/metre.
I just ran a 44/030 from the alt to the battery/power post on inner wing.
tabetha