First thing to keep in mind when running Index for money is that running a credit booster will make pretty much any difficulty massively profitable. Running higher difficulty will usually be 20-30% more profitable but chilling in low/medium difficulty stacking credit should be plenty of money to cover most of your needs.

As [Mesa] the only challenge you'll ever encounter farming the Index is basically finding enemies, this build solves this problem in a stupidly overkill way by giving you +90 [Enemy Radar] range.

[Intensify] lets you cap the 95% damage reduction on your 3rd skill, and [Vitality] is in there for extra survavibility. Everything else is to make sure you can spam Peacemaker without having to [Hunt] for energy orbs too often.