For now, IFC6410, quad krait.
This rpi stuff is boring as hell. Cheap sure, but in this case, you really do only get what you pay for, which was obsolete even before they came up with the idea. It would be far more interesting if they actually updated the hardware to keep at least consistently far behind the "current standards".
If your objective is running a graphical desktop, rpi is useless. About its only use is in automation/remote control.