Buying baby mattress and pushchair

Hi, i've spent a lot of effort trying to look for the most appropriate online shop to order this mattress for future baby:
kadolis 60x120cm coco and latex
Has any of you ever purchased this mattress or something quite similar from kadolis or greenweez or cmonpremier.com? I find this product mostly from France but couldn't find it in any physical shop to go see and get it.

Secondly, I've looked a lot for pushchairs and shortlisted a few.
I would still like to know if you have favorite websites in general to order such items for a good price and good delivery services?
I don't want to buy them in belgian baby shops because the choice is too limited, price gen. higher and didn't appreciate the service in one large shop in Zaventem and Drogenbos... (In general I'm used to the low quality of services in Belgian shops, that's not really the worry)

Thank you