hobart n-50

Hi , I've been looking at the n-50 for months and have a couple questions. I know they have a long history. The ones I have seen can have spiral dough hooks or D hooks but hobart doesn't show the spiral hook for sale ,so do some machines come with them ?  Some machines have bowl locks , but I don't see them on all recent or all new models ,what is that about ? Plus some have a stainless paddle on them but again I don't see that at Hobart's site .Is that an option or does it go with some models. I don't need an n-50 to mix cement but want a good model for dough,and by the way , everyone talks about mixing cement with n-50 ,That would not strain even a KA machine ,we aren't talking about a thick mixture just an abarsive mixture ,it would wear the agitator and bowl but not stain the motor  ,I've made plaster in my Kitchenaid before . One of the regulations for testing concrete requires use of hobart n-50 so that is why industry uses them. I have never seen one in person and will probably buy from webrestaurant.com  shipping and tax still gets it to me alot ( $ 700-1000 )cheaper than from hobart in canada although they won't honour the warranty. ( when I think about that it makes me wonder about hobart's business ethic's )

Regard Ggage