Custom Editor for a node based on type
The WYSIWYG module allows embedding any supported WYSIWYG editor to a field via a hook_form_alter()/hook_form_FORM_ID_alter() invocation. Here's a link to its documentation page. You can alter your custom node type form by altering the its body field #type &amp; #format elements.

Note: To do this it also requires:


The WYSIWYG libraries pre-installed to the sites/all/libraries directory.
A pre-existing WYSIWYG profile created.


As such, you'll need to have add a wysiwyg dependency in your module's .info file and some how do the above work in #1/#2 inside your  hook_install invocation.