Overview

"Books", all amounts, reports, etc., are in the main accounting currency
Set of additional currencies accepted on a per-agent basis
Packages have fixed setup and recurring prices in each accepted local currency
When purchased, conversion rate to main accounting currency (and original amount stored for references)

Configuration

Under Configuration -> Settings, set the currency configuration value to your main accounting currency, if not USD.
Under Configuration -> Settings, set the currencies configuration value to the list of accepted additional currencies.
Under Configuration -> Billing -> Currency exchange rates, set the exchange rates from each accepted currency to the main accounting currency
Under Configuration -> Resellers -> Agents, edit each agent and enable the currencies accepted by that agent
Under Configuration -> Packages -> Package Definitions, use the "Per-currency pricing" price plan and set the fixed local prices

When adding or editing a customer, set the "Invoicing currency" dropdown to the desired local currency

Line item reports show the local billed amounts as "Setup billed" and "Recurring billed"