WooCommerce expert for adhoc work - retainer possibilities for the right candidate.

We are looking for a WooCommerce expert to help us time to time on different projects with different issues :) We have in house WP designers cum developer but they don't have expertise in WooCommerce and thus we are looking to help on adhoc - as and when basis. We are happy to have the right candidate on retainer every month - permanently. Custom development expertise is a must have with woocommerce - we are not looking to get a plugin developed but developer should know the way around for multi currency, product addons, and how to make other similar plugins work around. Trouble shooting will be the majority of work.