is there any do it yourself homemade big brake upgrade i can do with si knuckles?
saw the dx and da stuff but i don't want to get new knuckles i just put new wheel bearings and studs in my hubs don't wanna have to buy all that again. https://honda-tech.com/zerothread/2211517 like this but si knuckles

also any thing for rear upgrade w/ swapping trailing arms?

 

the thread you linked to says it applies for 88-95 Civic Si without ABS. i doubt you have abs so you should be good to go.