Underbody and suspension coating: SO many options!?

[Josue]

I'm hoping I can get some help in choosing the right product to use on our '69 Firebird convertible project, there seems to be ALOT of choices!

It's your typical restoration project though, we're looking to paint the subframe, suspension parts, underbody, floor boards inside the car, axle, leafs, etc. So far, I've researched...

POR 15- Seemed like the front runner because of how well it looks on paper, and alot of people swear by it, but I've been reading about more and more problems with it not sticking to bare, sandblasted metal?

Chassis Saver- cheaper POR 15 knock off that I read some good reviews on, but also the same lack of bare metal adhesion problems as well.

PPG DP90- A PT and restoration shop we visited said they used this on all their projects, but something about leaving primer on a car doesn't quite sit right with me for some reason? I'm a body man, so all my years in the business have me used to seeing a car being primed, then immediatly painted. lol Can you really just leave bare primer on the underside of a car like that? Will it really last for years and years and years? Or am I misinterpreting this product's use of the term "primer" all together?

And I've read that all three of these need to be "top coated" in order to be UV protected, but.....none of the parts that will have these coatings will be exposed to direct sunlight, so how much of a problem is their lack of UV protection really going to be? Also, what do they mean by "top coat"? Do they just want you to base/clear over the coating? Or is there simply a "top coat" you have to buy and apply over the products?

And then there's a few random, "rust inhibitor" products that each person swears by, but that's what has me confused on what to go with, everyone's got a different opinion! This guy says he uses THIS product and swears by it....that guy says he uses THAT product because the 1st product didn't work for him, and he swears by it....the other guy says he uses THIS product because both other choices didn't work for him, but this one is perfect......you get the point. lol

And I know powdercoating is always an option, but you can't powdercoat the underbody of a car. haha And, PC'ing doesn't stop rust from forming, but if you PC blasted parts, will this really be an issue? And in the same fashion, I've found some negative opinions on PC'ing, stating that rust was forming underneath the powdercoat...so it seems like that option has it's con's too.

Help a newbie decipher all this conflicting info!!!