Javascript Builder Pattern vs Options Object for contact importer

Two popular patterns for configuration in JavaScript are the builder pattern and the options object pattern:

Builder

var importer = new LeadImporter()
    .assignLeads(true)
    .source("source")
    .organization(organization)
    .setLeads(leads)

importer.processP().then(function() {
    ...
})

Options Object

var importer = new LeadImporter({
    assignLeads: true,
    source: "source",
    organization: organization
})

importer.processP(leads).then(function() {
    ...
})

I'm trying to decide which to use for the design of a contact importer.

My gut is that the options object pattern is a better fit because the importer is configured up front and not piecemeal or over time (for which the builder would be better suited), but I want to do whatever is more idiomatic javascript for this particular usage.

Additionally, I believe the leads should be provided as an argument to processP() instead of set on the importer object so that the importer can be re-used on multiple sets of leads. Does that make sense?