I stuck with a new OEM HB because I trust Toyotas QC <Y2K
Im not suggesting the aftermarket items arent good or better in some cases, but unless you are talking about a huge power race engine, I dont see the need. And then consider that certain HB's dont fit well and will possibly need machining out to get over the snout of the crank, and I know what one Im choosing.
Most of us own fast street cars, that go to the track from time to time, so Im sure the oem HB will suit anyone else in this category fine too.
Given most 2JZ's are almost 20 years old, I would consider it an extremely smart idea to get a new one on there asap, unless its clearly been replaced in the recent past.
P.S Buy a new HB bolt at the same time.