You could get R31 house gear, Or go S13. Or be SMART and buy the set-up I am suggesting. I ran it in three cars. Please read this thread for some shock absorber education http://www.skylinesaustralia.com/forums/Sh...01-t114718.html
personally, as an ex-R31 owner, I can recommend a setup that I had. These bilsteins at wholesale, with the springs they supply, or you can select a height or rate through their supplier, This is the ONLY person who can supply R31 Bilsteins, and they are cheap! Rebuildable, awesome. Will drive heaps better then most of the coilover trash for even close to the money. http://forum.r31skylineclub.com/index.php?topic=104802.0
They also have the GTS strut tops which are legal. I had these, they did the job, and are legal. They adjust camber/castor http://forum.r31skylineclub.com/index.php?topic=127858.0
I also had whiteline swaybars, good rubber, same front calipers as you, I recommend Racebrakes RB74 pads or QFM A1RM. They are the best pad I have driven on for a spirited street car(Better than many EBC, better than Endless SSS, better than many Bendix). I loved that setup.