I just decided to go with using a Tabular Form on a view that I created in the PL/SQL database. There are a few complications with dynamic data but I'm currently trying to get around that.
Apex 4.0 will have what is currently being called 'Worksheet' which will bring in native dynamic editing of tabular forms. You can have a look at including ExtJS, like one oracle guru has done: http://apex.oracle.com/pls/otn/f?p=200801:2006 He's got dynamic content entering with a 'popup' field.. but his editable grid page is 404'ing at the moment.. unsure where it is.