Is this the right thing to use to paint my cab?

[oem4me]

Though the technology/spray quality is improving on various airless sprayers like that, the resulting finish may be more attractive on your fence or patio furniture than it would be on your truck. This of course depends upon how critical you are and what look you are seeking.
I recently used an inexpensive airless sprayer to blow a bunch of paint onto a vintage camper that needed some love. Besides producing minimal overspray, it actually came out way better than I expected. Then again, my hopes were low to start. Had the camper not been treated to a coat of house paint in it's past, I would never have considered this as an option.
If you already own the sprayer, definitely give it a test on something else first. There's way too much work involved trying to undo a botched paint effort, not to mention the crazy cost of materials.