Bunk beds-stairs or ladder?

[Doodle4]

I am desperately trying to decide if we should go for bunk beds with stairs, like the Kids Funtime Beds, or the Ikea Kura hack to turn it into bunks. Child on top is 4yrs old-I know the recommendation is 6yrs old but they are reasonably well behaved and we need the space!
Those that have bunk beds with stairs instead of the ladder, was it worth the loss space and do you feel it is safer? I would like to purchase a bed that will last them many years so I keep going around in circles about what is best! Any help?

If you have the space for it - we had something very similar to this www.amazon.co.uk/Checo-Ltd-MATTRESS-INCLUDED-Mattresses/dp/B07RLSH7DL/ref=sr_1_5?keywords=bunk%2Bbed%2Bwith%2Bstairs&th=1&tag=mumsnetforu03-21&qid=1645783176&sr=8-5 but a previous design. Was bloody solid and both my kids coped well with it, but it was huge. Think we got it when they were about 4 and 5 and the 4 year old has major coordination issues as well and the only issue we had with it was that the top bunk resident discovered she could drop books down onto the bottom bunk resident to wake them up and get her to read her a story!

Now they wanted more of their "own" space but still have to share a room - we've moved to two mid-sleepers so they both have a den/dumping ground for mess underneath.

The safety consideration for us has been the age of the youngest, we're waiting for now as he can already climb up stairs at 1. We've found one with high sides that looks promising as it contains them a bit better but, again, not tried it yet as they aren't quite ready.

We had stairs in a small room - the bottom of the stairs almost touched the opposite wall, but the ladder was so much harder to use. I suspect it depends on the height of the bed. Our medium height cabin bed was fine with vertical ladder (still with a deep tread so comfy for bare feet) but child with the high bed really preferred the angled stairs, and just stepped over them.