Mining lasers are still a thing, but are not needed for core mining, which is highly profitable once you get the hang of it, and pretty profitable even when you have no clue what you're doing.
For core mining you need a pulse wave analyzer in a utility slot, a seismic charge launcher (class 2 hardpoint), abrasion blaster (class 1 hardpoint), a refinery, a cargo slot, and a prospector limpet. To find the hot spots you need a detailed surface scanner, and collection limpets are nice to have as well, but it could be done with out those modules.
An optimal mining build for core mining for me would need at least 6 internals for the 2 limpet controllers, refinery, DSS, cargo, and shields. I've used both a Phantom and Python. The Python is in my opinion the optimal deep core mining ship, as you can have everything you want and need for the task, 200+ tons of cargo, left over hardpoints for real weapons to fight off npc pirates, and a gold paint job.