Steam alone on carpets is not good enough.
Never tried it with vacuum but cant really see it doing a deep clean.
Have you got any machinary at all for c/cing?
If not, whats the budget?
You dont want to start of wrong cause it will cost in the longer term.
Have you had any traing?
Training courses like NCCA (National carpet cleaners association) usually have machines on hand for you to try, and they explain the pros and cons. On a course like NCCA you may also get experianced cleaners so you glean off them.