I hear your frustration. I think they have only given you the simple screening test that is done to justify doing the sleep study. It is not a given that you will fail the actual sleep test. Here are my thoughts:
First, if you are paying it may be worthwhile to look around to find a sleep clinic that will do a home study instead of an in lab study. Much less expensive, and the results are valid for normal uncomplicated apnea. And if you fail the sleep test, some clinics will insist on an additional titration study to determine what pressure your CPAP should be set at. If you have basic obstructive apnea that is really not necessary. It is better to just buy an automatic APAP machine which is less than $100 more, and it will determine the pressure you need.
Sleep clinics can charge outrageous amounts for a machine. On line a get started package is around $800-900 for the automatic APAP machine, hose, and mask. But, if you can buy a "used" or little used unit, or be given one, that is better still.
If you end up needing a CPAP, I normally recommend a ResMed machine. However, if you are going to use it in a truck and I expect run it on 12 volts, the Respironics Dreamstation machines are nearly as good, and they run on 12 volts. ResMed machines want 24 volts and they charge $130 or so for a 12 volts to 24 volts converter.
Hope that helps some, Any questions, just ask...