Best practice will be to sync leads to SFDC using auto assign rules, and then build lead assignment in SFDC. For troubleshooting you might assign a field such as "Territory" to identify where the lead should go.
Queues are not fully supported by Marketo, and you won't be able to see the queue name as the lead owner. Unless you immediately re-assign leads from the queue to lead owners, I'd recommend assigning directly to users rather than queues.