This supply train is designed to supply all the parts an outpost needs. It works by enabling the supply stop when the outpost has less than 50% of the requested number of any item. Item requests are controlled by the constant combinators. Loading is controlled by reading the train's inventory. Each item has 1 stack inserter whose stack size is set to whatever however much of that item still need to be loaded. You can customize what items it loads by changing the constant combinators of the loading station, as long as you also change the stack inserter's stack size filter to match the new item.
Note: each outpost by default requests at least 1 of each item, so if you're not producing one of the items, the supply stop will never disable itself when it's full of the other items. So, if you're not producing, for example, oil refineries, you'll want to remove the refinery inserter from the supply stop blueprint.