hmmmm, very tough. If you haven't got your monitor yet, I'd go with an In-Dash unit. (Xenarc)
That radio won't have Aux-in plugs, how do you plan to do your sound? If you trash the radio, (and use an amp only) I'd put the In-dash monitor there.
If you keep the radio, where would you put the AC controls?
Maybe put the in-dash up top, where the r.vent and that gizmo is?
You have a tough decision dude.