Carrying my 8yo - which carrier?

I have an 8 year old son with autism. When he was a baby and a toddler, I carried him in a sling and later in a carrier. We both loved it. Recently we've had a few situations where I realised it would be really useful if I could still sometimes have him in a carrier. I've looked into preschool carriers (Tula, LennyLamb, etc) but I'm not sure he would fit. He's about 25 kg and 1,28m now, and I feel like he might grow out of the preschool carriers very soon already. So I'm wondering if anyone has any experience with any of the bigger carriers?

(I'm in Europe btw, so looking for brands that are available here.)

Thanks!