If I werent in panic'd rush I'd be looking for a decent used horizontal boring machine. Biscuit would be a waste of time and never hold the joints together especially if they were going to be raised from horizontal (bench) to vertical or transported to a job. Disaster. Tight domino's would be fine, overkill, still require some clamping. Pocket screws will not handle a lot of movement/racking/transport either.

A horizontal boring setup with a couple of dowles (preglued or not) would give you the absolute best face registration and zero l/r registration to account for on assembly. If you dial in your dowel to hole size clamp time would be in the seconds range I would guess.