The most common swap is the Electronic Distributor fitted on later L-series motors L24E, L28E etc.. These are Hitachi units and have a module on them E12-80.
Found this listed at $300 USD
I recently bought this Mitsubishi made distributor (I've got 2 now).
These are harder to find, but the build quality is a lot better. I paid $300 AU for the last 1 (not rebuilt) so the first link is not a bad price for a Hitachi unit that was rebuilt. In my opinion don't mess around with second hand ones - unless you plan to rebuild it. The Hitachi unit has a ball bearing cage that breaks and the vacuum advance is often stuffed. So they don't run that well, although probably still better than a points distributor.
Here is another option on eBay.
Cheaper than above.
Another option that's cheaper is the petronix ignitor here:
But it only makes sense if the distributor itself is in good shape and not flogged out, worn shaft etc.. This is also a good option to keep the "stock" look if that floats your S30z boat. I've never used this option myself.
If I was you, I'd probably look at the Hitachi unit on eBay but I can't vouch for the remanufactured unit's quality as I've never bought it.
If going turbo in future and planning to run an aftermarket ECU like megasquirt etc..I would look for a 280zx CAS style distributor. We have discussed this before.
But you'll need the ECU to use this, so might not be an option right up.