This method was outdated so I am replacing it with a link to BlueHands website which has some updated information regarding the Volvo conversion.
Published 2007 Updated 2020
Blue Hands Inc. Caliper Options
Sadly his page points back to 311s.org
Also, Spriso Motorsports offers a 300ZX big brake conversion kit. Info can be found on his website. Contact him directly for information
As to the stock brakes they work just fine. The only recommendation I would make is to have the pots re-sleeved with stainless by Karp's Power Brake out of Upland California. Unless you change your brake fluid regularly the stock pots end up going bad eventually. The re-sleeved stainless will last a very long time. Last I heard Karp's was having issues getting the rubber rebuild kits but to me this makes more sense than buying new OEM pots every time they start leaking.