You can find a customization info for ezwebin here:
http://ez.no/doc/extensions/website_interface
http://ezpedia.org/wiki/en/ez/overriding_the_ez_web_interface_ezwebin_with_custom_designs http://ez.no/developer/forum/setup_design/ezwebin_multiple_domains_and_different_designs_for_each
How many hours you use on implementing a template from a template site highly depends on your knowledge of eZ Publish. yes it's more complex then v2.0x, but it also gives you a lot more flexibility. Styling a ezwebin site shouldn't take more then 5 hours if it's the same basic structure. More flexible menu layouts has existed as patches for a long time so it just depends on resources to get it included.
