Is it 52cm from the corner of the seat crease, or from his position in the current car seat? Because if it's from the seat crease, you're taking a risk with any forward facing seat so it would be safer to go with a rear facing one, or move him to another position in the car.
Let me explain where it comes from - as part of the process to get a car seat approved, car seat manufacturers have to put their products through a crash test. As part of the crash test set up, there is a bar placed at this distance, 55cm forward from the seat crease. See attached, an image used in the legal guidelines to demonstrate. (For i-size seats, it's placed at 50cm, although currently there aren't any i-size seats harnessing higher than R44 seats unfortunately).
If the crash test dummy hits the bar, the seat fails the test. You will always get some degree of forward movement in a crash with a forward facing seat, but modern seats employ all kinds of methods to try and reduce this movement as much as possible.
Does that mean that your child is definitely going to go exactly 55cm forwards out of the seat if you did have a crash? No - not necessarily. It just means that provided you've installed the seat tightly enough and harnessed the child in correctly, they will come no further forward than 55cm. Hopefully, with a well-designed, highly tested model the companies themselves are going to design a bit of leeway into that - if I was going to design a seat myself, I probably wouldn't be satisfied with a 54cm head excursion just in case that extra 1cm caught me out on the day of the legal test! So you'd hope that with a decent quality seat you'd not be getting anywhere near 55cm of head excursion, and 52cm may be absolutely fine. But 55cm is the line where you can say yes, this is definitely a safe distance to install a child seat. So if you have less than 55cm space, you might want to think about whether you do want to use a forward facing car seat there, or not.
If you've measured from where his face is, then you'll be fine - plenty of space over the 55cm minimum!
Of the three seats suggested, I am not as keen on the Cozy n Safe, I would only recommend it if you need something especially narrow or lightweight. Joie Bold has been tested by ADAC and only got an average safety rating, but that might just be because it's a seat for an older child and of course the bigger the dummy = higher forces involved. BabyAuto Dupla hasn't been tested by any independent agency but they do seem to design and test their own seats at a university lab in Spain and so I'd put them at a similar level of trust to Joie.