For someone who wants to avoid Pathers (bugs aside), I like at least four planets:
* Two low hazard worlds (100% or less). One for Heavy Industry with nanoforge, another for Fuel Production with synchrotron.
* Two worlds with Mining. I do not think there is a single world with both ores and volatiles at +1 or more, and organics. Lower the hazard, the better. Will likely be from 150% to 200% hazard.
Low hazard worlds will also have Farming and Light Industry. They cannot use other useful Industries without attracting Pathers.
At least one Mining world will have Refinery. Other useful industries would be Farming, Light Industry, or Heavy Industry without nanoforge.
All will have at least Military Base. Low hazard worlds will have High Command. Higher hazard worlds might need to upgrade to High Command if alone in the system. All of them need to be able to defend against the neverending stream of raiders from pirates and majors, unlike core worlds who only get raided by pirates.
If mining world is in the same system as a low hazard with High Command, it might get away with Commerce or another industry instead of Military Base. (I do not get Commerce if I store ships there, due to extra clicks needed to access storage.)
With four planets, that means max Colony Management, and max Industrial Planning to meet demand and get max profit from four worlds.