Hi missy,
Both of these are only the slats and would need a bed (like one of these) to go with them to put the slats on. Without a bed the slats would be on the floor. If you had the bed to put them on and the slats, then either would be fine and both of these would work well. With the combination you could put the mattress directly on the slats.
In general you would be looking for a slatted foundation (or a bed with slats) where the slats were a maximum of 3" apart. A steel grid foundation can also work well. There are quite a few posts in the forum that talk about the many different foundation options and the benefits or suitability of each so I amalgamated them in this thread so you can see all the different options and price ranges that are available.
Phoenix