I would go with a brush on product as it is hard to get and even finish with a spray can on a surface that is laying flat as spray cans just don't do well at that angle.
I would go with a poly as the finish as sanding selaers are not desgined for long term durability but need a good finish over them. If you lay the doors flat and brush them they will look good and the brush marks will level out and be gone. Just be sure to buy a good chinese natural bristle brush to apply the finish.
Moderated by Handyman 
