Upgrading suspension before new tires?

[phook]

I have a 2.7 that is stock except for GT3 brake ducts, a roll bar extension, and short shifter kit. I also got a performance alignment from a reputable shop, but was only able to achieve like -0.7 camber on the front.

It is not a DD and I primarily use it for autox/hpde/canyons. I do a handful of autox events per year and maybe 1 HPDE. I don't care about getting a trophy or anything, mostly just racing against myself.

Currently running Bridgestone Potenza S-04 PP. Front tires have some life left, but rear tires have almost no tread left. The outer parts of the tires are pretty worn down on both front and rear.

I wanted to replace the rears only, but can't find the same tire in stock for my 17" wheels. Thinking of getting RS4s all around, but I was considering upgrading the suspension so that I could prolong the life of the tires (especially the outer edges).

My autox times are somewhere in the 70th percentile, so I certainly still need a lot more seat time. I've been trying my hardest to follow the mantra of seat time > mods, but it sucks that my tires go to **************** due to the outer edges wearing out so fast.

Plans for suspension upgrade were:
B8 shocks/struts
H&R Springs
Tarret camber plates
Rear toe arms

While I was down there, I kind of wanted to change out the sways and drop links as well, but maybe I'm getting ahead of myself? Should I go for shocks, springs, plates, then tires, and then sway bars/drop links down the road when I need to fine tune the handling? Or just do it all at once?

Second option is to just replace the tires again, ruin another set while I get more seat time, and upgrade the suspension later?