Help me prepare for body work before I dive in

My Jeep needs a new windshield. I took a few rocks last winter and managed to crack it straight across my line of sight. Sucks as it's a 2 year old windshield but such is life in snowy country. While I have the windshield out I want to fix this little bubble that has popped up. I've not done work like this before. I've got the tools and that's it. I'm hoping to cut out a rusty section, bend up a piece of sheet, weld it in, prime and paint.

What gauge of metal and/or what's a good donor?

What are the correct steps to seal/prime/paint?

Is there a place to buy a small amount of this exact paint code? Or do I go to the local body shop and see if he can mix?

Cut out and replace with metal

If you can, make sure you clean the back side of the weld since it has a layer of oxide on it.

Define and area about 2-3 times the area of the rust and feather out the paint.

Coat with epoxy and scuff.

Apply bodyfill and sand down with 80 grit.

If metal show up as high,  make it go away with a hammer, add more fill and sand back with 80 grit. Stay with 80 grit until the repair has the shape you want and is flat.

High fill sanded first to 180 then 400

Spray with topcoat.

Going to cost  a bit because you will have lots of extra materials for such a small fix.

There is a possible new way to do this but I can t vouch for it. Evercoat makes a high fill called Super Build 4:1

Might eliminate the need for both epoxy and filler. Just shoot it on and sand it flat and smooth to 400 and paint. YouTube videos available

http://www.evercoat.com/optexsuperbuild/us

Just came here to say... NEVER take body advice from me.  If I post bodywork advice, chances are I'm rip-roaring drunk, having a stroke, or otherwise full of various, questionably-legal substances.

Good luck, god speed, and may the force be with you.

I had good luck with these guys for small quantities of color matched paint and clear. Also bought hi build primer from them. 
https://www.automotivetouchup.com/

My concern is that after having used real automotive paint materials, I dont ever want to use spray bomb stuff again.

NOHOME said:

My concern is that after having used real automotive paint materials, I dont ever want to use spray bomb stuff again.

While most spray bomb paint sucks, you can get proper paint mixed and put into a can. I did that a long time ago and it was great for a small surface. 
 

The real key is to keep the nossle with the best spray pattern. 

What goes onto the bare metal? I've been told about sealing it or etching it or something different? The Jeep lives outdoors and get's the snow scraped off with a shovel and pushbroom. I'm not in this for perfection but waterproof and long lasting and as good as I can realistically make it look.

Thanks for the step-by-step NOHOME. Very helpful.

I like the looks of the color matched rattle cans.