Duracoat and Durabake are great because you can purchase it, and apply them yourself (I did my Saiga AK stock and forearm with them). The problem with them is they do show wear and they scratch. My opinion (for what it's worth) is to go with the Cerakote. It is much more resilient, but can only be applied by Cerakote trained professionals. There are a couple of folks on ebay that offer Cerakote jobs for uppers or slides, but the Cerakote website lists all Cerakote trained technicians by state so you don't have to worry about shipping lowers while complying with FFL regulations if they are located close to you.
Somebody quoted you $189 for just the slide? That's extremely overpriced. I own a shop and I use cerakote almost weekly, I use it for automotive applications not guns, but I did cerakote a few of my own guns. Dura coat is more user friendly, cerakote isn't all that tough to apply but does require some skill and the initial output of things you'd need to buy wouldn't be worth it unless you had a bunch of guns to do. Cerakote definitely handles scratches better and is more durable but if you're looking for something on the cheaper side and quicker go with the duracoat. My opinion is bias because I work with the stuff every week but I say go with the cerakote if you have the option but don't pay $189 for a slide that's highway robbery.
Juice, I looked into doing cerakote a while back and it was pretty expensive. Can I ask you to guess at what it would take to setup something to do small parts like pistols now a days. I've done molly resin, duracote, gunkote, hot bluing, and parkerizing before and have what's needed for those precesses.
shaggy, if you want to do something like duracote, gunkote, or moly resin you will need a way to remove the old finish, sand blasting is the best. FYI not bead basting. Blast the metal parts only. Not the polymer.
Polymer just degrease real good.
Then you need:
1. rubber golves
2. air brush. I used a cheap harbor freight one
3. acetone to degrease the parts.
4. finish (molly resin, duracote, gunkote etc..)
5. black wire to hang the parts to paint and dry.
I personally like molly resin it's the toughest finish I've used. Draw back is you have to bake it so it's not polymer friendly.
If your baking I would suggest going to a thrift shop and getting a used toaster oven large enough to fit you parts and a good thermometer.
Sounds like you have everything, sandblaster, compressor, paint gun, airbrush gun, acetone, degrease tank, hanging wire, oven( if you do the H series) that's pretty much it, watch the videos on cerakote.com it'll show you everything