Bag it or paint it?

you don't have to buy 'drop shocks' you can buy whatever size shock you need from any shock company, such as monroe for example. you can get your shock relocators and install them, and measure the extended and colapsed height you'll need and call and special order shocks to fit exactly that size (plus about 1/2 inch on the extend and collapse) or you can buy shocks first, and mount the lower mount to the axle/control arm, and find a place to mount to the frame for the upper mount. i suggest the first option.

you might want to run a different pressure switch for those compressors, as they are rated to 200psi and those slambags are rated at 200psi also.

the difference of a triangulated 4link and a wishbone is simple. the tri 4link has 4 link bars, with 2 (usually the uppers) setup in a triangular shape.
a wishbone has the same or similar 2 lower bars, parallel with the frame rails and the upper bar is a wishbone, like the wishbone in a chicken or turkey...
refer to previously posted picture for triangulated 4link
here's a quick example of a wishbone setup.

Ah! So basically, the difference is that the upper is one unit and the difference of 1 link. Lol. Okay, cool! I read somewhere that if I went over 145 psi for viair that it would void my warranty?

If I get 8" bags for front and rear will they fit in the mazda? And I still would like to know:
Do I need a solenoid for the compressors?
Will I also need a relay for the pressure switch?

you'll need 1 relay per compressor, and loop that thru the pressure switch and i recommend a toggle switch in that loop mounted in the cab, so you can turn it off and on manually too.
i don't know why viair would make a 200 psi compressor if it were only supposed to go to 145. does that make sense to you? not me. a 380 is rated from the company to go to 200.
an 8 inch bag in the front? no way dude. not unless you are planning some major work! get a 6 inch dia. bag. and it'll fit with minimal work. you can run whatever you want in the rear for the most part. go nuts!

The dual pack from retro, includes the relays... What do you mean loop it through the press. switch?

What would be the problem in having the compressors on for the ignition? Cause it would be on, but only run until pressure is too low. A little confused...

Ok, so I gotta change the press. switch, no biggie...

The only reason why I ask about 8" bags, is because if front is 6" and back is 8", won't the rear have more lift? I like even ride height!

So if thats true, I guess both will have to be 6".

your air ride is adjustable. you don't have to ride @ max or min height. you can run the front at 10psi and the rear at 190 psi, or vice versa, or whatever.
go to this website to check out a wiring diagram for the compressor.

i personally don't like the compressors wired to the ignition, because they won't run without the key on. it seems more practical for them to be on a toggle.