I couldn't find GDM settings in Configure Your Computer-->System, but I logged out and was able to go into session and change it to XFCE, so yes, apparently in installing those dependencies it DID end up giving me the entire XFCE desktop environment, as I can and have now just booted into XFCE, but I don't want to settle for one or the other; I want my custom DE. I'm starting to think maybe I should just go find a pure openbox remaster over at the project forum. I could start with that, download lxpanel, thunar, xfdesktop and lxdecc, and just create a startup script to run lxpanel and xfdesktop at boot...
EDIT: by 'the project forum' I meant the community project site at mypclinuxos.com, in case that wasn't clear