This a common upgrade for MX-5s/Miatas, replacing the factory coil/ignitors for Coil on Plugs from Toyota Corollas/Camrys/Yaris's/etc..
There are a lot of install guides on the web so I won't delve into that, but below are compatiable part numbers for the Toyota/Denso coils.
It provides a much better spark for boosting applications and can sometimes work out cheaper than replacing a broken coil-pack, not to mention it's more compact and neatens up the engine bay. I would recommend buying them second hand from a wrecker instead of generic stuff off eBay. If you're planning to run it on a stock ECU than you should use a dwell reducer so the coils don't get damaged, for standalone ECUs you just need to set the dwell timing lower.
You can also buy brand new connectors for them, I ordered mine from here:
Below are some photos of my COPs wired up.