I think you'll be happier with the Midwest pen, and great score on the vinyl flooring!
I would NOT put whelping pads on it, however, the whole point is that you want your puppy to be able to differentiate between potty and "not potty" (AKA "the floor"
) You don't want anything on the floor that he may think makes a comfy potty spot. He needs to save that for his pee pad tray! In the beginning, depending on how well potty trained he is when he arrives, you may need to close the pen down to a smaller space (one section by 2 section usually works well) with his bed in one end, and the potty tray on the other end, with very little open floor between. When he is successful with that arrangement, you can slowly increase his area, until he is successful with the pen opened fully.
The climbing thing is funny. Some puppies are very determined climbers, others have no interest in climbing at all. All of mine, as adults, could easily just JUMP out of my 24" ex-pens. none of them do, however. That is their "home base", and they respect it. My opinion on taller ex-pens for our small breed dogs is that VERY few puppies actually "jump" the pen. They climb the inside and tumble down from the top. If they can climb a 24" expen, they can scale a 48" expen, and some ARE that determined. They stand a much greater chance of serious injury falling off the edge of a 48" expen than they do the 24". So I'd stick with the 24" size, (they re easier for humans to step over!
) and just be aware that IF you have a climber, you may need to cover it.
I'm a fan of crates in the bed room. Kodi slept downstairs, in his expen with crate attached for his first two years, because my husband was still in his "dog hater" phase. Now they ALL sleep in our room, in their own crates. I know that many people choose to let their dogs sleep in bed with them, and I actually sometimes let mine sleep with me if Dave is away, or if we're in a hotel room at a dog show. But I would never let a puppy sleep on the bed, even if I thought my expensive mattress wasn't in danger. There is just TOO much trouble a puppy can get into while you're asleep. (remember, supervision and confinement are your puppy-training friends!!!) Even if they don't go looking for trouble, it is too easy to roll over on a small puppy, and even a fall off the bed can permanently injure the soft developing bones of a young puppy. They are safer in a crate, and feel comfortable right near you. Both of our breeders started our puppies in crates at night shortly before they went home, and we didn't have a peep out of any of them, even on the first night. We did have a few middle of the night "potty calls" in the first week or two, but even those went away very quickly.
This was Kodi's "bed room" for his first couple of years. It did have the advantage of him being completely independent for early morning potty trips... He never needed us to get up with him, because he just had to toddle over to his litter box when nature called! Oh, that was a 30" expen, and the only one I ever bought. (and wished I hadn't!) I'm tall, and it was a chore to step over to clean up spilled litter or clean the litter box.