Harvey
I'm speaking as a porty user.
Everything others have said about HydraMaster is true. There service and product are superb.
They also do some terrific deals which may well be worth enquiring about. For example, thay have good working relationships with many different vehicle suppliers and are able to pass on tremendous deals for a new van and machine combo. They'll also recommend someone who can set up different types of financing for the package if you so desired.
This will give you a good starting point for you to consider all options.
If you are confident in your sales and marketing skills, along with your existing client base, then I feel a T/M is the way to go. It will certainly be cheaper than employing another technician and supplying another van and porty etc.
Obviously, there are other T/M manufacturers out there who can offer competitive packages too. Another avenue you may wish to explore.
Safe and happy cleaning

Ken