About to order the BC coilovers but was reading that the coils that come with the kit are weak and that going to 9k/12k springs is the better route. my question is where can i purchase springs rated at these ratings??
You should be able to specify the spring rates you want when you purchase the coilovers. Check with the vendor.
As for bushings, you don't need need to replace anything when you install the coilovers, though some owners will take the opportunity to replace the front strut mount bushings. You may want an extra set of front strut mount bearings while you're it, since they often come apart during the install if you/the installer isn't careful.
You will need to clock/index the control arms, however. This is done by loosening - not removing, just loosening - the mounting bolts for the front control arms and rear control arms, toe rods, and even the trailing arms, I believe. Complete the coilover install, put the car back on the ground, then tighten all the above bolts once the car is on the ground at the new height.
Ok..... I emailed BC about wanting to go with a higher rated spring (9k front and 12k rear) they told me they can do 9k up front but could not do 12k in the rear. So where can I get there spring ratings I'm looking for to work with the BC's???
You should be able to get 12k springs for the rears. If not, then maybe BC has stopped making them. I don't know of a company that manufactures springs for other company's coilovers. So if you can't get them... Then you might want to look at a different brand, period.