The red tail Looks closer but you never know the yellow may go first. It depends of the fish and the stress level of the fish
I would put some java moss in the breeder box but you must have it very very loose so that the babies will still be able to fall though( the mom wont be as stressed if there is a little moss in the tank.) You will have a high drop if you make the fish have the lest stress. I believe it is best to heavily plant the tank ( fake plants and real ) when the fry are born you just move them . This is just want I do.
If you would like to see a pic of my tank that I breed guppies in just ask.