Big dilema for next bed

Hi everyone, my wife and I are thinking about getting a new bed for our 7m old. First he had the bassinet which he has outgrown very fast, now it's a classic wooden crib. The problem we are facing is that he's a decent size lad (2ft 7in) and started grabbing the railing while seated to get himself up. He sometimes gets himself standing or sort of standing and falls, for now only backwards back in the crib which is not great for his head because as i said it's a wooden one. Worse would be falling forward. My wife already struggles getting him in the bed while he's sleeping because she's small, so moving the mattress lower would put a VERY big strain on our backs while trying to put him in the crib after falling asleep and again it's the fear that he'll hurt himself trying to get up. Now to the dillema, we were trying to decide between a pack&play with the mattress all the way down (the ones we're looking for are those with a detacheable side so our backs will be more pleased) or a regular baby play pen where we would put his crib mattress (coconut). The mattress would be exactly half of the playpen so we could get another one for it to be basically a square bed on the floor. Have any of you guys done such thing? Is it safe? What should we do? Thanks!