The white one looks to be more complete, less exterior work, interior looks to be in better shape, the tail lights and garnish look to be in great condition.
First thing first ..
CHECK FOR RUST!!!!!
Then question any repairs.
Start with the front guards, cheack along the top of the guard where it bolts up to the car for rust, also down the bottom of the wheel arch where the guard meets the rocker panel (sill panel)
Move on to the fire wall, check there is no lifting or bubbling along where the water channel runs, and down both sides where the inner guard and fire wall meet.
Make sure the battery tray and underneath the tray havent rusted.
Check the A, B and C pillar, around where the venting is
Check along the gutters at the roof edge
Run your hand along the length of the rocker panels feeling for rust bubbles
Have a look inside the boot/trunk down along the floor pan where the rear 1/4 panel meets the floor pan for rust, dirt and muck usually get caught up there and retains water rusting out the 1/4 panels, check up under the rear parcel shelf along the windows, also have a look up along the rear 1/4 panels either side around where the C pillar and parcel shelf are, rust can form along there interally.
Check the rear tail lights where they mount up to the rear facia, under along where the hatch seal runs, check the floor pan in the boot where the spare is located.
Check all doors for rust
Pull back or lift up if possible, the interior carpet and check the floor pan for rust.
You will be VERY fortunate, to find a rust free 120Y, you need to find one that has the least, especially if you want to restore the car withoiut too much cost.
Just from the pictures, the white one would be my choice.
Hope this helps a litlle

EDIT:
I just realised I was describing a sedan, not Coupe!
LOL, still, most of this will apply.