Based on everything you’ve told us about yourself- firearms experience, property access and distance, financials in place, and firearm use at your type of work, you've got all the ingredients already in place to just dive into this hobby head first. I can tell that you’ll learn fast, and be a seasoned vet in no time. I’d also say a year from now you’ll probably own up to 6 PCP’s, especially once you discover the sheer pleasure of shooting a fine piece of workmanship, typically more accurate than the powder burners you already own.
Yes, for sure try the cheaper Ammo and see if it works, but when seeking top tier Ammo look at FX, JSB, H&N, AA, and many more.
Trenier Outdoors is a great place to buy Ammo, and the big 4 are great places to source parts and pieces- Airguns of Arizona, Pyramid Air, utah Airguns, Airgun Depot.
Start hanging out in the compressor and tank section as compressed air is the lifeblood of a pcp, and to learn the ins and outs of being air independent is an apprenticeship all its own. Safety is key with high pressure air
Welcome aboard. The folks that chimed in before me on your welcome are great “go to” folks with a lot of knowledge