Scott is dead on as always. You can do a very good Job with just a grout brush and a mop and bucket. It will take you a very long time unless you are not concerned with the results just the $$$$.
If your only concern is to get the money out of the home owners pocket and into yours then here is how you do it.
Buy some
Prochem Tile and Grout Cleaner or Viper Venom. Lay it down strong and thick with your mop and bucket.
Take your Grout brush and scrub as fast as you can east,west,north and south.
Take your two jet wand with a
Glide on it and rinse the Floor
Change your mop head and give the floor a last step rinse with a neutral cleaner and collect your money
If cheating your customer isn't how you want to do it then you can't do it with a 200 psi porty. At least not anyway that will be profitable to you and fair to the home owner.
You can however get a portable capable of tile and grout and carpet cleaning with heat for under 3500.