Compact cot, cot or cot bed?

Second time Mom but confused!

Need opinions please.

So for my first baby we bought a cot bed- as I can use it for a long time...and still do...she is 4 and still sleeps in it as a toddler bed( in her own room)

For second baby I have a Chicco Next to Me ( which is roughly 95 cm long) but as he starts to sit up is time to get a cot.

Problem is LACK OF SPACE in our bedroom. And still want to keep him in our bedroom.

So I ha e been looking at COMPACT COT which is 100 cm long but they say that is up to 1 year. And my baby boy is quite tall already.

A cot which is 120 cm long would fit but I don’t see how 20 cm make a difference?!

How long can you use these types?

Ideal would be a cot bed but no space for it