this wood is eastern white pine.
These should be sturdy enough for bed slats. I would choose these over the furring strips.
Have You considered asking Home Depot?
I don’t see the option online to buy the whole bundle but I’m sure if you ask at the pro desk they can help you. I would advise caution if you buy a bundle since there are always warped or damaged boards in each bundle. But again, the pro desk can help you with informed decisions.
I have had Home Depot cut countless boards and plywood for me over the years, so yes I would say they will.