I'm not sure if you're really asking but I see question marks in your brakes first, brakes first ? line.
If you are seeking advice or opinion, I would counsel do the suspension first.
These cars have pretty good brakes compared to rest of the car.
I did a couple track sessions in my 05 on stock brakes. Did not hurt anything.
I noticed more return on investment with suspension.
And make sure you pair those Eibach springs with good dampers in one shot.
Saves you having to go back later to finish the job.
I'm very pleased with Bilstein HD's. They're designed for lowered cars. Properly tuned.
If you need to make room in your budget, I would hold off on those GT500 front lower A arms unless you have bad bushings and have to replace for safety reasons.
The stock A arms are very beefy from the factory. GT 500 are the same except stiffer bushings, but still rubber.
Difference here will be marginal only. You will get more benefit from dampers.
Another great add on that will get you good benefit is Maximum Motorsport caster camber plates.
Reason is that these replace the rubber upper strut mount with a spherical bearing.
Keeps the top of strut from deflecting in cornering. You will notice this benefit more than the A arms.
Also best time to do this is while doing springs and dampers, to keep you from going back in later.
If you need to make more room in budget to accommodate this, wait on the sway bars.
You can always do the sway bars at a later date convenient to you without affecting previous work.
You don't have to pay labor twice.
Adjustable panhard a big plus with poly bushings. You will notice this difference instantly, plus re-center rear axle on lowered cars.
Rear LCA's with relocation brackets also big plus to restore traction on lowered cars.