Hello, nice to hear from you.
You won't regret. I'm also leaning toward to offer only coatings from now on, thanks on easy of use and effectiveness of PBL coatings.
I hardly recommend for you to do at least one of your vehicles (or a hood at least) before offering to coat other people's car. It's easy to apply no doubt, but it's somewhat 'tricky'. You have to get the felling for that.
Hope you've ordered 32oz of DP Coating Prep Polish to take care of all vehicles you're going to coat.
By my experience (ok, it's not huge!), 8oz of PBL Cleansing Polish is far away not enough for the 8oz PBL Surface Coating.
Another recommendation is for you to test Preping Polish Both by Hand (use a MF applicator) or by machine (use a polishing pad).
I say this because depending on temperature, Preping Polish may dry fast and cause some dusting by machine, which is not desirable when you want to finish down right away with the coat.
I mean, any dust on crevices and residues have to be removed, and you'll have additional work removing that dust.
For application, I've found it easier with round yellow foam applicators (like I've saw Mike Phillips applying somewhere) than the LC applicators. This is another reason I'm telling you to test on your vehicle before offering to others. Try to decide which way is better for you to apply.
I haven't bought the PBL shampoo yet (I'm from Brazil, to worth any order at AG I have to spend at least $200-$300 every time), but it may be really interesting if you pretend to offer maintenance for the cars you've coated.
Looks like 8oz goes a long way, it's extremely concentrated. For now, I'm using conventional 'wash & wax' shampoo' without any adverse effects I can notice (at the 'macroscopic level

)
If there is any topic I couldn't cover here, or if you want to talk more about it, please, feel free to ask / contest anything I've said.
I'm also learning, and I always try to do the best I can on my detailing part-time job. All information we can share is very valuable.
Thank you in advance,
Kind Regards.