just a small point here, sacs do cover you to take clients stalking if you buy their business package.Most of them don't cover you if make money from your stalking ie taking out clients BDS one does but only up to a maximum of I think its £2500, so yes they are OK for recreational stalkers but if you take clients even if its only an odd one to help with costs, you need a bit more than what the shooting organisations provide.
I would also check if you are covered if you sell your venison, I am not sure about this but it could be classed as making money.